doomkernel

You could try VanillaOS or BlendOS. Both immutable and allows you to install whatever package you want from any distro.

Don’t know much else.

Tier lists are opinion-based, but I don’t share yours

You can use bob (a neovim version manager). It requires rustup though

There is a fork of OpenBoard which is pretty active the repo is on github. It release an update a day ago

Finally! A free storage solution!