I have a question: every now and then a -2 is subtracted from my reputation because something was removed from a question I wasn't even involved in. For example: -2 was taken because something was removed from some question about how to model some sort of sphere. I had nothing to do with that question. So why is bse associating me with it?

@Nate_Sycro27 did you edit that in the past?

you get +2 for edit approval when you're below 2k

Do you lose reputation if the edit is rolled back?

@Nate_Sycro27 that's a guess, yes.

one loses reputation when someone rolls-back the edit. Can't say for sure the deletion.