On the schedule you've got listed, I don't think you've really got time for both Death Valley and Yosemite, if you want to make it from Pahrump to San Francisco the same day. Your plan to get up at dawn, when the day before you want to be in Vegas after dark, and then drive another hour and a half to Pahrump for the night, also seems to be an issue.

If it's me, I'm spending one less night at Grand Canyon - you'd still have nearly 2 full days there - to spend at least one night in Yosemite, both to see some of the park, but even more to break up the drive.