To be honest, I think it's hard to have this discussion in the abstract, because a lot of it comes down to what that "specific level of creepy" means, both on the individual level and culturally. I think to what degree sex, violence, drug use, antisocial behavior, etc., are acceptable in media depends a lot on the context.

Many, or rather most, of the popular manga/anime series out there are shonen shows, primarily targeting the tastes and sensibilities of adolescent boys, so I think to some degree sexual content and violence are to be expected.

What's more, I think America is generally more sensitive to sexual content in media than Japan, while Japan is probably more sensitive to stuff like drug use... so there is a cultural aspect to it as well of course.