Distro suggestions
I would recommend EndeavorOS too, easy to install, sane config, nearly pure Arch.
Testing out Artix right now - I wanted to try out lightweight init system.
System76 or Framework laptop?
I wish they had 10 inch option. Something like GPD Win Max 2, but without gaming features
Portable console producer GPD in talks with Valve about using SteamOS.
By "weird" hardware you mean proprietary modules like fingerprint scanner, gyroscope and etc?
Can Wine / Proton / any translation layer run games from external drives?
There are no C/D/... drives in Linux. Steam and Lutris create their own environment ("bottle", right?) for every game. I think by using Lutris you will get the most user friendly approach.