Tires: my opinion, carry a spare. I have a complete mounted steer tire that can be used in any position. I would still have to call a tire service to change it as i don't have enough air supply for a big enough air gun to do it myself, and am just plain too lazy to do it manually. This way at least I'm not over the barrel for whatever they decide they can get me for on a tire. And most importantly to me, my tires still match and I don't have 5 of my michelins and one of whatever brand they happen to have. In my particular case I have an odd size 22.5 that is usually on a freightliner class A motorhome chassis and I figure not every tire shop will have one. At a very minimum I would suggest carrying an unmounted spare that matches the rest of the tires, for the same reasons mentioned above. I have to give my Dad credit for that idea, he always carried an unmounted spare in the basement compartment of his class A, that way he has a matching tire to install without the weight of a mounted spare.
Towing: AAA premier RV will tow up to 200 miles on one tow per year, 100 miles per tow on remaining tows. I drive long distances and it may be some ways to a place that can work on the truck and I figure one bad towing bill would pay for 10 years of AAA, plus it still covers you on all your regular vehicles in addition to the RV. Of note is that it covers the member, not a specific vehicle, so you are good on any vehicle you happen to be riding in even if it is not yours.