If you want to crazy with the keyboard, consider switching to Dvorak instead! It's an investment of course, but you get used to it surprisingly quick and the typing experience is a lot better. As for the function button you can always just remap them to your preference, I don't see the point in making a fuzz. Most distros are also made with a PC keyboard in mind, not that I know if that matters.
As for GNOME vs KDE, it's up to personal preference. I enjoy my GNOME setup a lot, running just a couple extensions to get it just the way I like it. I enjoy that there are very few options and distractions around that I am not interested in. And I of course understand that other people prefer KDE. It's great that there are two dominant DEs with such completely different design philosophies.
You cannot view microblog posts from Lemmy, so the only way you'll see anything from Threads is if a user from there responds to content posted to Lemmy or similar sites. Possibly also if they choose to tag a community in their post, but that seems unlikely for anything else than testing purposes.
Same as Mastodon users, really.