it really matters if you have something soft like a z rated tire, those go quick.
yup. the softer the tire rating, the faster wear will be. the harder the tire rating, the less it will rare.
soft tires grip better than hard tires (so perfomance is better), but hard tires last longer
not really, with technology on the rise today and the new materials we're using in our high performance tires, they are lasting just as long, if not longer than low performance tires.
just make sure you guys rotate your tires every 6k-8k miles, check your tire pressures every week, if not every 2 weeks, alignment every 10k miles or so, or when you get new tires/wheels, and make sure those tires are balanced!
this will ensure proper tire wear to get your money's worth!