6 week trip itinerary - but I have some specific questions

I agree with others that you are close enough to the eastern states and should skip those attractions on this trip and focus on seeing as much as you can out west. The Moab/Arches NP area is spectacular as are the other southern parks in Utah. Having deadlines kills a trip so try to loosen up on the schedule. You may get somewhere and not like it and get tom another spot and want to spend more time. Have fun and relax! Safe travels!