It's not on the unsuitable list, it's on the limited suitability list. So it's not as badly regarded as subjects like media, film, buiness and ICT, but it's also not as well regarded as your other subjects- it's somewhere in the middle. You'll be fine though. I got an offer from Cambridge with 1 A*, 6 As and 3 Bs at GCSE, AABB at AS and my subjects were French, history, English lit and sociology, so 3 suitable subjects and one limited suitability, which I think is the same as you'll have. You really don't need amazing grades and all highly respected subjects to get an offer.