I can’t help you much as I have a 6600XT, but I can say this is probably the wrong community to get that help. It’s not likely KDE-related.

Before going back to windows, I would boot up an arch-based live iso to see if newer drivers cleared up your problem. I use EndeavourOS, and that has a graphical live environment and should give you a good idea whether your card is working or not. Good luck!

In its current state? Not unless it gets heavily marked down (KSP2 does have better tutorials and a more accessible progression system).

With the studio being shut down, it’s likely that what we have now is all we’re getting.