My commute to work and then back home is an average of 50 miles per day @ 24.1 avg MPG, however 70% of that is highway, and 30% city.
I have a VERY hard time not going into boost, its just too much fun. I think the car eats up tires like crazy though, probably due to the power and FWD. Last night I was accidentally riding the clutch to bump the revs to make a turn light and did a quarter mile burnout instead. I was like oh crap, my bad! Looking in my rear view to make sure no cops saw that.
Slightly over the speed limit? Not sure what you are talking about but I did some independent wind testing on the MonsterSpeed3 Halloween Teeth I used on the car to see at what speed they would break loose. Used 3M Velcro and they stayed secure at 100+
There is a decent sized back cargo area, and a lot more if you fold the seats down. But not as much as a Mazda 5.
As for this "Mazdaspeed" version it was a turbo version that has been discontinued for the new body style, so if you want the turbo version you would need to find a pre-owned model.