You'd be fine with 5w30, and although the brand you use is pretty much a matter of taste (as long as you change it regularly,) I would personally use Motorcraft synthetic blend, because it's a better oil than nearly all the dino oils out there, and costs about the same. The wix filter is fine, although next time I would use Motorcraft, as it's cheaper and pretty much the exact same thing.
I would definately take it to the dealership to have that rattling fixed. While in there, might as well ask them if there's any new pcm programming or anything they can do before the warranty expires.