I don't think you can go wrong, but one piece of advice I'd offer is to cut more than you think is reasonable from your itinerary. The trip to GC and LV is fine, but will take more than a day. If you plan on going to Canyonlands, Arches, Canyons of the Ancients, etc, each of those is a day. You might consider planning a general loop that starts/ends in Denver, hits Moab on the far side, etc. I'm not sure where you want to go in CO, but you could day trip through Cortez/Durango/Silverton/Ouray/Buena Vista/etc on your way back to Denver, or swing further south and hit Great Sand Dunes, Pikes Peak, etc if you did the San Juans on your way west. Save NV, AZ and NM for a separate trip. Every time we plan one of these, we start out with this long ass list of things we want to do, then cut and cut and cut as the plan starts to materialize and we realize there's no way we can fit all the things we want.