Kurenai doesn't have a bloodlimit, she sucks. It's just the way her eyes look. No vest cause of style, they just have Choji's clothes fit him when he's big, cuz having his fat ass show by making the clothes rip on the multi size to make it more realistic would just be dumb. The chuunin exam was different back in the day I think, and the genin weren't as talented. And Naruto was never stealthy to begin with so it doesn't really matter if his clothes don't blend in.