I read the whole thing, our system is fucked.

I’m using KDE and when I download a flatpak it automatically creates a .desktop file. I think gnome does this too if I’m not mistaken. I do have to restart or relogin for it to put the file there but that’s not that bad IMO.

Librewolf is able to do that by turning sync on in the librewolf settings.

I am reading the wiki, but it is mostly discussing PulseAudio and not providing much information about PipeWire. I am unsure whether they share similar file locations or configuration processes, and I do not want to arbitrarily paste PulseAudio commands without knowing their potential effects.

My headphones are not Bluetooth, and I have already disabled the EQ. Disabling the EQ has not fixed my problem; it has only made the sound slightly more bearable.

According to the Arch Linux wiki, power-saving mode for my audio card is disabled by default. I have not enabled it yet, therefore it is not currently available as an option.

How can I check that? Is there a program that I can use or a command?

For some reason i still have bad mouse lag on x11 but it could be nvidia or my driver for all i know.

I would say Debian, its stable and customizable.