Saw the edits and I would like to congratulate you on the start of your journey.
All of the stuff you mentioned works very well - OBS is native, (and if you miss the performance of ShadowPlay, somebody made a replacement!
qBittorrent is native (and IMO the best) and the vast majority of games work on Linux now!(ProtonDB is a great resource for seeing what works and what does, and it even has a profile feature where you can plug in your Steam account username so it can automatically show you what’s compatible!)
Mods are slightly finicky, but SteamTinkerLaunch will likely be able to solve all your problems, and r/linux_gaming has numerous discussions and workarounds, including this very recent and relevant one!
Have fun, and try not to get caught up in distrohopping!
Thanks, Google!