I agree that not all good teachers have to be blooming extroverts with booming voices. Kids respond to all kinds, and as long as they know that you love them and your subject matter, and that youre in control, it's all good. But if the impression you give is meek or timid (even if you're really not like that) they maybe wary of hiring you. Could you practice interviewing with a friend and maybe get feedback on how you're projecting your voice?
As for the commute, that sounds like something they could ignore if they were satisfied with everything else.
Good luck. I know how hard it is out there.