Tyre Replacement Using Treadwear Warranty

I'm one of many (I think) with a car that eats tyres prematurely despite correct alignment and pressures, and non-aggressive driving patterns. A recent post reminded me to take advantage of the treadwear warranty I have, and this thread is a friendly reminder to dot i's and cross t's -- since there are quite a few gothcha's involved in taking advantage of the warranty:

1. Seems common for manufacturers to require proof of good maintenance. This means tyre rotations about every 5k miles, and keeping tyre pressures within spec. A couple of shops I called told me that they do not try to stick to the letter of the warranty rules but rather expect reasonable conduct from the customer. It seems rather clear that using a shop that will not try to nitpick the customer is a good idea. Because of these requirements, trying to invoke a warranty from a shop other than where original purchase and rotations take place is going to be an uphill battle.

2. An employee at my shop tried to tell me that the credit is a prorata of the *wholesale* price. I called multiple stores in town and they all told me that the current msrp should be used. Hopefully a chat with the owner will straighten this out for me.

3. I was thinking about using Costco (since I can retrieve tyre rotation records), but they will only provide warranty service on tyres bought from them. It was interesting to hear from them that they do not charge their usual $11/tyre installation and disposal fee in cases of warranty replacement. It makes sense to me that these fees should at least be prorated also. I might try and request it from my shop.