Sorry, to hear about all of your problems. It all started with the halfshaft bolts. Mine were going to fail sometime too and still may. I got the part replaced by the GT Guys, but that may not be good enough. The bolts were still tight, but the washers were severely bent!
I think the main problem is that good workmanship at the service dept. are non-existent. A minor problem just keeps growing as you bring the car back to the dealer. Many cars are not repairable by the average tech in the service dept. They are built in a certain order on an assembly line by people doing the same thing everyday. The tech rarely sees a GT so everything is a learning experience for them. Do you want someone to get an education using your car?
I would either send the car to Saleen, have the GT Guys fix it, or lemon the car.