1997 Lincoln Town Car Routine maintenance vs. Repairs defin

I would appreciate a definition from a certified automobile expert / professional regarding the difference between routine maintenance and what items and actions generally fall under this category, and automobile repairs as pertains to a vehicle as a whole. My sister is a developmentally disabled person that I've been caring for for years and she is in a program that will pay for our primary vehicle repairs- (non-routine) as stated in the program standards and guidelines, but it won't pay for routine maintenance. Recently, upon hand washing our vehicle and tires / wheels, I discovered that the sidewalls on all four tires had cracks around the whole or most of the outer sidewalls. I contacted Michelin and they directed Discount Tire to do a detailed inspection of my Michelin tires that still had well over half of their tread life left. Before discovering these cracks I certainly had no intention or need of replacing them based on wear. After the detailed off-the-car inspection some of the tires had cracks on the inner sidewalls. Michelin offered a 50% adjustment towards a new replacement set of tires based on safety concerns and wear and tear was not a contributing factor. Also, the car is generally under a carport and not exposed to direct sunlight that could have possibly effected the outer, but not the inner sidewall. What I need is a professional determination as to whether replacement of tires under these conditions is considered a repair as pertains to the vehicle as a whole (in order to ensure my sister's safety - as provided for in the program and), or is this considered routine maintenance. My position on this matter is that this is a non-routine vehicle repair, as routine maintenance as regards tires - as I understand maintenance, is ensuring correct tire pressure, checking tread depth and for uneven tire wear, and dong scheduled rotations and balancing. As a side note, this program will pay for someone to wash a vehicle for a person unable to do this themselves due to their physical disability. My thoughts on that are that the vehicle could simply be taken to a car wash, and it doesn't get more routine than a car wash in my mind! Also, this program previously paid for the replacement of the intake manifold on our car due to it cracking in the front crossover area and leaking coolant causing the car to overheat and was also a safety issue (safety is a factor in this program) due to the fumes that would enter the vehicle, so replacing an item in order to effect a repair of the vehicle to keep it on the road is still considered a repair. Some items can be repaired and still work and others need to be replaced to repair the vehicle. The fact that the tires were replaced (and not repaired) should not factor into this. Where this program runs into problems is that routine maintenance is not covered, but repairs- (non-routine) - as they describe this coverage, are covered, but they often mistakenly interchange the terms 'maintenance' and ' repairs'. Your professional opinion on this is greatly appreciated.