Nissan engines and transmissions are pretty tough and reliable, which would be the weakest links if I were concerned and debating on a warranty. The TPMS is way overpriced from the dealership you went through and though they typically need to be rebuilt when replacing tires, there is little other maintenance typically required. As for the R&P there is no reason to believe it will fail prior to 100k, honestly, the dealer is full of it.

I see no reason to purchase the warranty.

Also, to be clear, the Maxima is not the most expensive Nissan outside the 370z or GTR, you forgot the whole Infiniti line and the Nissan Armada. All in all Nissan's are not too bad, but they tend to be poorly equipped as rentals and their electronics are pretty dated in comparison to the competition (like for like in model year terms).