I'd say not to worry so much about the dress code. Look nice, but don't sacrifice comfort. When I interview people I notice if they look uncomfortable or are fidget-y. A little nervous-ness is expected but you never want to look like a fish out of water. As for the hand-shaking, do what feels natural to you. And when all else fails follow the interviewers lead, they're not trying to intimidate you (in most cases haha)