Well, it's about as slim as you can get for one of these things; it's really just a strip of leather folded around the phone, with a belt clip attached to one side. Not too bad.

Yes! Since the top of the pouch is left open, just insert the phone with the headphone jack pointing up, and you're good to go. (You can even still work the volume buttons, something I didn't expect: the elastic webbing at the sides is so thin, you can easily press the buttons through it.)