AFAIK the only infinites that have ever been singled out and banned in the US are Tekken 5.0 Steve's infinite, and dead-body infinites in Marvel (since they guarantee a time-out win after killing 1/3 of a team). Well, that and some Smash stuff, but Smash is its own planet compared to the rest of the US scene anyway. =P
Japan does it a bit more, but this varies depending on the particular community. Infinites tend to be banned in SNK games, and Arcana Heart also banned all infinites, but games like SF2/Marvel/Melty Blood/Hokuto no Ken never banned them.
Character bans are similarly rare. The US used to insta-ban any console characters back when arcade was still the tournament standard, but that practice has obviously died out (thank you SC community for moving to console first, btw). Other than that, it's mainly just ST Akuma and some (not all!) SNK bosses, who are broken on a level well beyond any SC character. Well, there's also Akuma in HD Remix, but:
1. I don't agree with that ban, as he has nowhere near the amount of tournament dominance that, say, Metaknight does in Brawl. And even the Smash community ended up not banning Metaknight!
2. Metaknight & HDR Akuma are both still stronger than anyone in SC4. Metaknight has no counter-picks, period; Akuma has maybe 1 or 2, Hilde is probably the same (and her main strengths are stage-dependent), and Algol definitely has more than any of them. You could even argue that Eddie in Accent Core is better overall than Hilde or Algol, and the thought of banning him has never been entertained in the slightest.
tl;dr - Nobody in SC4 is "broken" by the standards of fighting games as a whole, no extra rules are necessary.