I get "503 Service Unavailable" on your links. Any commented lines in the removal script will be ignored, and those commented packages will not be removed. Everything else should be removed.

I'm not sure what you mean. It's not the exact same list of firmware, but many are the same. Here's what's in the installer isos (this is from a mounted netinstall iso). These are actually symlinks to the packages, which are under /pool.

$ ls mnt/firmware
amd64-microcode_3.20160316.3_amd64.deb                firmware-ivtv_20161130-3_all.deb
atmel-firmware_1.3-4_all.deb                          firmware-iwlwifi_20161130-3_all.deb
bluez-firmware_1.2-3_all.deb                          firmware-libertas_20161130-3_all.deb
dahdi-firmware-nonfree_2.11.1-1_all.deb               firmware-linux-free_3.4_all.deb
firmware-amd-graphics_20161130-3_all.deb              firmware-misc-nonfree_20161130-3_all.deb
firmware-atheros_20161130-3_all.deb                   firmware-myricom_20161130-3_all.deb
firmware-bnx2_20161130-3_all.deb                      firmware-netxen_20161130-3_all.deb
firmware-bnx2x_20161130-3_all.deb                     firmware-qlogic_20161130-3_all.deb
firmware-brcm80211_20161130-3_all.deb                 firmware-realtek_20161130-3_all.deb
firmware-cavium_20161130-3_all.deb                    firmware-samsung_20161130-3_all.deb
firmware-crystalhd_0.0~git20120110.fdd2f19-1_all.deb  firmware-siano_20161130-3_all.deb
firmware-intel-sound_20161130-3_all.deb               firmware-ti-connectivity_20161130-3_all.deb
firmware-intelwimax_20161130-3_all.deb                firmware-zd1211_1.5-4_all.deb
firmware-ipw2x00_20161130-3_all.deb                   hdmi2usb-fx2-firmware_0.0.0~git20151225-1_all.deb

That could possibly be accomplished with some creative symlinking.

I think you can get away with two or three partitions. Root filesystem and optional /boot partition on the ssd and /home on the spinning disk. Install everything to the ssd first, with /home as part of the root partition. Then manually edit fstab (and crypttab, I guess) to use the spinning disk as home. Move the new /home to /home.bak or something, so you keep the new config files in case you need them. And maybe make a backup copy of the old config files, in case they get lost or changed. Using the old config files with the new system may or may not work properly in all cases. It'll be trial and error until you get everything the way you want.

I forgot about swap. You want it encrypted. You could either use a swapfile inside an encrypted root partition, or you could make a new lvm on the ssd that includes the swap.

Caveat and disclaimer: I hate the debian-installer enough that I maintain my own installer.

Take a look at my post with examples of raid/lvm/luks with refractainstaller. I don't know how to do such a complex setup with d-i, but I'm pretty sure you could do it similar to one or more of my examples.
https://dev1galaxy.org/viewtopic.php?id=2323

If you want your home spread over both disks, then you need to have both disks (or at least part of each disk) included in the volume group (or in a raid array). Then data will be written to both disks (striped). That may increase performance.

If you then want /var, /tmp and swap to be only on the spinning disk, they need to be in a separate lvm or raid array (or not in the volume that includes /home.) The same would be true if you wanted them to only be on the ssd. If you're ok with them being spread over both disks like your home, then one volume group will suffice.

If your lvm is inside an encrypted partition, you can still change the sizes of the logical partitions inside it. This way, everything is encrypted and you enter one password for the whole system. If you want to make the lvm bigger than the physical partition that contains it, you would add other drives/partitions to the volume group and then extend the logical partitions within.

If you're concerned about excessive writes to the ssd, then you probably want to keep it separate from the existing lvm, so it doesn't get used for any of your more active partitions. (When you add drives to a volume group, the combined space is seen as a single container, and data gets written to all parts of it.)

I believe it's possible to do what you want, but you might need to do some of it manually. I've done encrypted lvm installs before, but I've never done it with an existing lvm that had data on it. See these two threads (and some of the links in them):
https://dev1galaxy.org/viewtopic.php?id=674
https://dev1galaxy.org/viewtopic.php?id=2323

The procedure in the debian-installer for encrypted lvm is not at all intuitive. It goes something like this:
Make an encrypted volume from a partition.
Use the encrypted volume for lvm.
Create the logical volumes inside the lvm and assign mountpoints and filesystems for them.

For reference, here's a video of making an encrypted partition, without lvm. The "4" on the end of the file name is because it took me four attempts to get it right, even though I've done it many times. This will give you a sense of the logic used in the installer.
http://distro.ibiblio.org/refracta/misc … rypt-4.ogv

At the boot menu, press 'e' to edit the boot command. Add the word, nomodeset, to the linux line. Then ctrl-x to boot. That usually fixes the black screen.

I tried it again, this time pulling cinnamon from ascii. It seems lightdm wants consolekit, but there's a way around it. And you're right - the power buttons in lightdm don't work, but shutdown/reboot/logout all work from the desktop. I did not install the cinnamon metapackage. I installed what you showed and then had to add cinnamon-core. Something may be missing. It all works when you choose cinnamon from the tasksel window in the installer. Maybe looking at the list produced by aptitude -s install task-cinnamon-desktop would provide the answer. (I'm looking at it now, it's long, and I don't see anything related to consolekit, policykit or elogind.)

Anyway, here's what I did.

# apt-get --no-install-recommends install elogind libpam-elogind
Reading package lists...
Building dependency tree...
Reading state information...
The following additional packages will be installed:
  libelogind0
Recommended packages:
  policykit-1
The following NEW packages will be installed:
  elogind libelogind0 libpam-elogind
0 upgraded, 3 newly installed, 0 to remove and 5 not upgraded.

# apt-get --no-install-recommends install lightdm
Reading package lists...
Building dependency tree...
Reading state information...
The following additional packages will be installed:
  liblightdm-gobject-1-0 libxklavier16 lightdm-gtk-greeter
Suggested packages:
  iso-codes accountsservice upower
Recommended packages:
  desktop-base gnome-themes-standard policykit-1
The following NEW packages will be installed:
  liblightdm-gobject-1-0 libxklavier16 lightdm lightdm-gtk-greeter
0 upgraded, 4 newly installed, 0 to remove and 5 not upgraded.

]# apt-get --no-install-recommends install libpolkit-gobject-1-0-elogind libpolkit-backend-1-0-elogind
Reading package lists...
Building dependency tree...
Reading state information...
The following additional packages will be installed:
  libpolkit-backend-elogind-1-0 libpolkit-gobject-1-0
  libpolkit-gobject-elogind-1-0
The following NEW packages will be installed:
  libpolkit-backend-1-0-elogind libpolkit-backend-elogind-1-0
  libpolkit-gobject-1-0 libpolkit-gobject-1-0-elogind
  libpolkit-gobject-elogind-1-0
0 upgraded, 5 newly installed, 0 to remove and 5 not upgraded.

# apt-get --no-install-recommends install cinnamon-session cinnamon-control-center cinnamon-settings-daemon
Reading package lists...
Building dependency tree...
Reading state information...
The following additional packages will be installed:
  accountsservice apg cinnamon-control-center-data cinnamon-desktop-data
  cinnamon-session-common dbus-x11 gir1.2-cvc-1.0 iso-codes
  libaccountsservice0 libcinnamon-control-center1 libcinnamon-desktop4
  libcinnamon-menu-3-0 libcvc0 libgnomekbd-common libgnomekbd8
  libimobiledevice6 libmm-glib0 libnm-glib-vpn1 libnm-glib4 libnm-gtk0
  libnm-util2 libplist3 libpulse-mainloop-glib0 libupower-glib1
  libupower-glib3 libusbmuxd4 upower
Suggested packages:
  gnome-control-center gstreamer1.0-pulseaudio libcanberra-gtk-module
  cinnamon-screensaver isoquery libusbmuxd-tools
Recommended packages:
  libcanberra-pulse mesa-utils mousetweaks policykit-1-gnome pulseaudio hwdata
  usbmuxd modemmanager policykit-1
The following NEW packages will be installed:
  accountsservice apg cinnamon-control-center cinnamon-control-center-data
  cinnamon-desktop-data cinnamon-session cinnamon-session-common
  cinnamon-settings-daemon dbus-x11 gir1.2-cvc-1.0 iso-codes
  libaccountsservice0 libcinnamon-control-center1 libcinnamon-desktop4
  libcinnamon-menu-3-0 libcvc0 libgnomekbd-common libgnomekbd8
  libimobiledevice6 libmm-glib0 libnm-glib-vpn1 libnm-glib4 libnm-gtk0
  libnm-util2 libplist3 libpulse-mainloop-glib0 libupower-glib1
  libupower-glib3 libusbmuxd4 upower
0 upgraded, 30 newly installed, 0 to remove and 5 not upgraded.

I could log in, but that wasn't enough to get to the desktop, so I installed cinnamon-core. A lot more got installed here than what I'm showing, but no consolekit. I can now get to the desktop, and it seems to be working.

Reading package lists...
Building dependency tree...
Reading state information...
The following additional packages will be installed:
  at-spi2-core caribou cinnamon cinnamon-common cinnamon-screensaver cjs
  cups-pk-helper darkpurpy-icon-theme desktop-base dh-python dmz-cursor-theme
  gawk gir1.2-accountsservice-1.0 gir1.2-atspi-2.0 gir1.2-caribou-1.0
  gir1.2-cinnamondesktop-3.0 gir1.2-clutter-1.0 gir1.2-cmenu-3.0
  gir1.2-cogl-1.0 gir1.2-coglpango-1.0 gir1.2-gdesktopenums-3.0
<snip>

Yes, you can just download the package and install it. You might already have a copy of the package in /var/cache/apt/archives/.

If you want to install a minimal system, you could use one of the installer isos (not the live) and when you get to the tasksel window, un-check everything except "Standard system utilitites". Then you can add xorg and whatever desktop stuff you want after you boot into the new system.

If you want to start with the desktop-live iso, I suppose you could drop to console and uninstall the desktop stuff before running the cli installer. I've never tried that, but I think it would work.

Beowulf isn't really ready for use yet, but it is possible to use it if you pin some packages to ascii versions. See this thread: https://dev1galaxy.org/viewtopic.php?id=2301

You could be the first to try it with kde. If you do, please let us know how it goes.

I managed to install cinnamon from beowulf yesterday, but I can't tell you exactly how I did it. Basically, I installed from desktop-live, added beowulf to sources, removed xfce and slim a couple of times, installed cinnamon a couple of times (without recommends), installed lightdm and had to remove it and install libpam-elogind first, then I could have lightdm without consolekit...

Power buttons are working. I didn't try mounting removable drives. Here are some suggestions for you:

Use codenames in your sources.list. (beowulf/ceres instead of testing/unstable)

Install the devuanized policykit-1 (0.105-18+devuan2.11) and the missing libpolkit-backend (same version)

I got an error about some glib package that needed to be installed because of the newer libc6 but couldn't be installed because it needed a newer kernel. That's when I realized that libc6 was from beowulf. This is where mixing stable and testing can get ugly. You may run into some difficult conflicts with libraries.

In one of your pastes, I saw nm-applet and wicd mentioned. (.xsession-errors, I think.) I got rid of anything network-managy or wicd and installed connman, because that's the default when you install cinnamon from the tasksel window in the installer. Either way, you should pick one package to manage network connections, so they don't fight with each other.

For reference, here's a recent account of another trail-blazer who upgraded ascii to beowulf -
https://dev1galaxy.org/viewtopic.php?id=2301

Post the output of dpkg -l | egrep "consolekit|elogind|libpam|policykit|polkit

Also for apt-cache policy libc6