Having lived in the West all my life, I agree with most of the posters---you are planning much to much.

I was lured into doing too much last year by google earth in Ireland. Planning looked so good-less then 120 miles planned per day, 9 days to see a small island--right! After the fact realized I needed twice the time allotted to all stops.

My own suggestions of must sees are: Grand Canyon, Zion, Bryce, California wine country, SF. There's very little in Socal to interest me any more (born there), terrible (can not over say that) traffic.

I agree with the comments about the heat. Nevada, Palm Springs etc. is likely to be really miserable. Been through Death Valley, nothing there, HOT!

Good Luck!