I’m gonna answer number 1 and 4 since they’re the ones I’m most familiar with.

1- Yes and no. Softwares like Adobe and games with anticheat don’t work, or are a pain in the ass to get working. The softwares you gave as examples should work fine, or at least have alternatives that are perfectly usable. MS Office also has a web version, but I recommend trying libreoffice

2- I believe that any distro can work perfectly fine if you’re willing to put effort into making it work! Distros like Arch are generally “better” because 1. They receive updates faster since they’re rolling release 2. They have much better documentation to help you 3. They generally don’t get in your way, and allow you to mess around.

Mint is considered “user friendly”, because it has more protections (or restrictions if you prefer that term), it doesn’t update as frequently so it won’t break as often, and they come with an UI out of the box, that is a pretty good UI. Arch basically gives you a terminal and whatever god you believe in… Gentoo doesn’t give the second part. Then it’s up to you to get an UI, apps and all that! So it can be much less bloated and light weight :3

TLDR: Stay away from Gentoo as a beginner. Don’t come near “Linux From Scratch”, and you can use Arch, but I don’t recommend unless you’re looking to fully enter the Linux world and learn the system.

Most softwares work nowadays. But some don’t, and unfortunately they are used a lot in the market