So I am having a similar problem, alignments off, and I am not rough on driving. The tires won't last long and I have gone with several brands, they still couple. (sp) I will say Dealership was great with belts and replacement pricing. That was Gainesville GA Mazda. Cheaper than my normal mechanic. shocking.
I went from xterra to mazda3 hatch and it has a lot of room and it is like a sports car to me. I can still haul all the gear that I normally had with xterra.
Find a way to keep alignment on, and better tires that will last longer.