The only thing I will say about the rotations, is that I can usually tell when a car comes in that hasn't been rotating their tires, because the front tires will be rounded over on the edges, and the rears will be pretty flat, this is because with the fronts being the ones that steer, the camber is constantly changing on them so they work the edges much harder than they do on the rear. For the the first half of the life of the tire, this is not a big deal, but becomes greater as the tire wears overall, because you will see the edges of the tires start to cord prematurely on the front. In other words, it will cost you more money in the long run by not rotating them. This is one of but not the only reason why cars with staggered fitment wear at twice the rate as ones without, because you cannot rotate the tires. This can also create a potential issue on an AWD car, if you replace one end but not the other, now you have a tire that is a different diameter on one end vs the other which I've been told can cause an issue with either the wheel speed sensors or perhaps the differentials. I've never experienced this being an issue my self, but per the manufacturers, I have heard it is always best to keep the tires as equal in size as possible. Take it for what it is worth and make your own decision, because everyones driving habits are different.