Arch was the distro that got me to stop distro-hopping. It’s stable, it has a rolling release, and it’s mine (as in, customizable, manageable).
I guess, if there’s anything I wish I’d known off the bat is that the Arch documentation is probably the best available. So much so, a LOT of it applies to Linux in general and not strictly to Arch.
https://wiki.archlinux.org/title/Main_page
If something breaks, READ the error messages, understand each component, and check the wiki, there’s a very high chance the troubleshooting section has the exact issue laid out.
I also have a Surface GO 2 and been running Linux for the past 2 years. In the beginning the only “trouble” was that you you needed the surface-linux kernel for drivers, but that’s no longer the case as all drivers have been upstreamed to the mainline kernel.
For distros, anything goes as long as it has a recent kernel. I just go full Arch (EndeavourOS is also a good choice).
What you probably want to pay attention to is the desktop environment - i’ve found Gnome works best for touch and tablet devices KDE requires some tweaking.
For 2, check the flathub store, you might be impressed with what you find for note-taking and PDF editing. Definitely some good options out there for Linux.
3 is a preference. Generally use internal storage for OS and external for data. Linux doesn’t take that much space, so if with 120GB you’re having storage issues, just ditch windows, problem solved, lighter system.
4 Yes it works.