Questions about trip to S. Utah.

Planning on visiting this area in mid-April for about 3 weeks.  In researching the area and points of interest, there is much talk of hiking here, and hiking there.  Neither my wife or I are capable of much hiking other than for very flat and level hikes.  So, now that everything has been been planned and motels secured, I'm beginning to question just how much we might miss by not being very mobile.  Photographically, just how much will we see (or miss) by doing only drive bys, turnouts and overlooks, and the flattest of hiking trails?

Will I be OK with two lenses?  15-85mm and 70-200mm?  How about a fisheye?  I also have a Canon SX50HS (50X optical zoom), and a Canon sx230HS(14X zoom P&S).  How about those?

We'll be entering this red-rock territory by first visiting Mesa Verde, the South Rim of GC, then on up into Utah(Zion NP)

Any and all help is appreciated.  Thanks in advance.