miker71 said:

I've never really understood the relationship between Tarkin and Vader. Why is Tarkin able to command Vader and disrespect the force and belittle as a religion he obviously has no belief in? Compared to the Moff of the second death star in ROTJ who nervously receives Vader.

This bugs me a lot. Mainly because it's something that could have been very easily explained in the prequels, but guess what? IT WASN'T, in favor of overexplaining a lot of things that didn't need to be explained. Tarkin was in, what, a single, 3-second long shot in the PT? HUGE wasted opportunity there.