Whats it like to work at a bar?
and...
Are there any qualifications? Ones that aren't obvious like having great communication skills.

Bars smell bad, and so do some of the patrons. The music is loud, and you can't hear yourself think. If people leave money on the bar, it's not your tip! People say and do things in a bar, that they wouldn't do anywhere else. You don't need any communications skills, your body language is all that is needed.