All the parts you quoted make it non-free. Free software allows you to use and modify it for any purpose.

So proprietary

To this day, I still don’t know how to set a path variable permanently in any Linux distro

KDE Connect works on Wayland and can do all of that. Should definitely be technically possible.

You can see other people’s issues on ProtonDb https://www.protondb.com/app/485510

Basically no attacking with controller without workaround, movies not playing for some and performance/stability issues.

Lots of good games are still not working properly (e.g. Nioh), also modding support is very lacking and cumbersome.

I would say that NTR is quite unhealthy, and not every hentai exclusively has adult characters

Use Magisk, it bypasses SafetyNet. No need for dual boot https://github.com/topjohnwu/Magisk

You must install the Universal SafetyNet Fix afterwards https://github.com/kdrag0n/safetynet-fix