Ace,
I've looked at the Alpine IPA-W200 which is similar to the Pioneer you're talking about. I favor Alpine for their iPod controls... and it does all the same (nav w/live traffic, bluetooth, rear camera, DVD, HD/Satellite/AM/FM Radio).
In the recent Mazda Speed magazine there's actually a picture of the CX-7 with the Alpine unit installed and it looks NIIICCCE.
From what I know, the hazard button is NOT part of the head unit. Like I said, Alpine says they're going to have the dash kit available any day now, so that tells me the hazard switch shouldn't be a problem (of course I can't tell you for sure... yet).