[kadoban]

Depends on the distro, but it's trivial in ubuntu-based and no harder than the rest of basic setup in arch (the only two I have recent experiece with). I'd argue that any distro where it isn't easy is a good reason to start looking elsewhere, absent any specific conflicting requirements.

Not sure it matters if it's full-disk vs just home directory, but full disk is easier to reason about and I don't recall an OS that can do homedir easily but not full-disk (there very well could be one, just none come to mind).

[pinusc]

It can range from trivial to impossible. Full disk encryption does not play well with hybernation on laptops, for example. There is also very limited support for hardware encrypted ssd... And even though it can potentially be a few arch commands away, you need to do a lot of reading to understand what you're doing and make informed choices about your setup. Which is hard.