Yeah, universal destruction; although he really didn't show much. As he was starting to manifest in the 21st century it was stated that time/space began to collapse around ultra (past version of Infinitus).
There really aren't sufficient feats for Infinitus to gauge. We could go by implied power, but then again, Aegis was implied to be more powerful than the Beyonder...
Dnt think so,galactus did beat her and the other primordials together,though she may well have been equal to the galactus that they fought with since he wouldn't have been as sated as he was back then