Unfortunately the game logic is tied to the framerate, so the more balls I buy the slower the game runs the longer it takes to clear a level.
Yeah
I would refrain from buying too many Scatterballs because having too many of the single hit balls makes it worse
Yeah, I opted for only sniper and cannon balls after a few prestiges and it seems to pump out much more damage in any case. Only issue is with certain bosses where they have immunity to those balls.
Very true