Look at #2 in your complaint! They install THEIR brake pads! Would you take your own steak to restaurant and ask them to cook it? And expect to them to guarentee that it will taste as good as the one that the stakehouse uses? Do you really expect the shop to warranty brake pads other than their own? When I ran a shop, I would rarely allow customers to bring in their own parts due to liability issues. If the customer insisted, I would charge the customer the applicable labor guide charges and explain that there is no warranty. The labor guide charges will, in most cases, exceed a "coupon price". Most repair shops have a contract or promotion with the brake pad manufacturer used in their special pricing which allows them the ability to charge so little for the service.
Do me a favor, look up the Mitchell Labor time on installing brake pads, resurfacing rotors, and installing a headlight on your vehicle. Better yet, ask the dealer...and then ask them if you can bring in your own parts. My guess is that the auto shop in question didn't charge you enough.