The first service is just an oil and filter change and a tire rotation. You can look at your own fluid levels. 15K is the first service where you do more than an LOF and rotate.
The dealer would have to prove the aftermarket parts caused the suspension failure whatever it was. I think you need to find a good dealer. There are lots of dealers with employees who love to modify their cars and won't kick you to the curb for a few mods.
