I’m far from an expert but I believe Proton is specifically intended to provide compatability with Windows gaming tech like DirectX.

For regular non-game software you don’t need that tech, you can just run it through Wine itself (Proton is built on Wine). Bottles is actually what I see recommended these days (it simplifies management of Wine prefixes) and supposedly many apps can run in a few clicks.

Not strictly proton, but for wine, you can see here (https://appdb.winehq.org/) that it supports more than just games.

Lots, but if they interface with usb (like an image writer or mouse software) it won’t work.

Notpad++ works in Wine. And I used to run JMP 10 with wine too (data plotting software). Neither required Proton though.

I dunno about Proton but I’d assume do. I have some CAD and 3D software I use in Wine.

I’m pretty sure there are wine builds with all the proton enhancements that aren’t in normal wine yet. I feel like I saw in lutris or bottles or both but you can surely get it other ways too.