My only suggestion is to try to get to YS first and make the decision to either stay or go in time to look at the other sites (Sante Fe, Mesa Verde, Arches, Canyonlands). Been to MV - very cool but not worth a huge excursion. YS is a mega trip of a lifetime. Your schedule sounds excellent for 4 days - you must be rather intelligent! But do consider the option of bypassing the other parks for what is a life changing experience.
And eat as much of the huckleberry ice cream as you can get your hands on. Please send a pint to me if you can.