I've noticed a lot of "nice guys" are creepy and obsessive. So I'd like to know most of the common traits that give off that vibe.
Easy examples: 50 roses at your doorstep after a single date.
5 text messages in 5 minutes just because you didn't instantly reply to his text message right away.
Saying "I love you" when you barely know him.
Most Helpful Girl
It really just depends on how well the two know each other and how the girl feels about him. if she really likes him they can get away with a lot more. if she's hesitant on it then it's best to be guarded. I'ts also about how the thing is done. if executed confidently, then the chances of it not being creepy go up. but if done too confidently it comes off as being socially retarded because they seem to be overstepping a boundary.
As for some of the actually traits, too much physical contact seems to be what guys have a hard time with more then anything else. if you're repeatedly hugging a girl and she walks away or even gently pushes you off you need to back off.
as silly as it sounds, hygiene is a huge one. If you smell bad you're automaticly creepy, it doesn't matter how attractive you are. girls HATE being grossed out, if I see a guy so much as pick a scab or his nose or butt or whatever, he's out.
Being really distrustful gets annoying fast too. if she isn't answering you or texting back, you should leave one (hello? you there? ) message and that's it. unless it's been over 5-6 hours. and accusing a girl of lying or hanging out with other dudes without cause is bad...
Super super romantic things are best saved for when you've gotten to know each other better, too much intensity can make things uncomfortable