i was gonna try it just to test my patience honestly

you should still have something separate including the fishing achievements, it sounds interesting outside of journey mode

there should be a file that's like "achievements-steam.dat" that you should be able to open with notepad. you can erase your achievements by deleting everything in it with notepad. however, you should probably keep a copy of it somewhere.

FPS counter is ok, if you're talking about " icon bypass " then it should be fine, but if it's a texture pack, then no, and everything else isn't (as far as i'm aware)