I don't know if anyone feels the same, I find this question hilarious. Sorry if I offend you but to answer your question, no It isn't a turn off. I'd feel that he is really serious about the date till the point where he is too scared if he does anything wrong.
Nervousness equals self doubt and means you're a person who has some unsavoury beliefs or thoughts. If your comfortable with yourself you wouldn't be shaking like a jaky who hasn't had a drink in a while. It repels everybody coz most people know at an instinctual level what it means. Square yourself up and don't embarass yourself until you do.
I may sound like a prick for saying this but it's a huge turn off. I am not into guys who are afraid of me. It just comes across as odd, uncomfortable, and a little pitiful. I couldn't be attracted to someone like that.
No. I was just worried initially when he wouldn't sit down next to me but two chairs away (wasn't a date but similar situation). It's unusual but with time you get there and make him feel comfortable around you :)