Fsr isn't a magic bullet. Try setting everything on potato, fsr off, yand see how it runs. Should be like 50-60. If it's still giving you trouble, then something is wrong.

What is stable to you? I put mine on a combination of medium and high settings and I get 45-60fps. If you need rock solid, probably play on low at 50fps cap.

This isn't like an iPhone that has yearly updates. It's more like a console, which is updating every 3 - 5 years. Better to buy early than late