Thank you, Ben, Craig, and especially James - that's exactly what i needed to know. I've printed it all out for reference and found a few Red Rock climbing websites with additional info.
Tacky though it is, I just booked all our nights at Circus Circus ($22/night) and we'll drive out to Red Rock Canyon most days for bouldering. Maybe one day trip for a Hoover Dam tour and another (start early) day to Death Valley, depending on the temps that week.
My 12-year-old son and I like to do some serious miles (600+/day highway, 20-30/day on the trail). But my daughter likes to DO stuff - climb rocks, see animals, etc, so fewer highway miles works much better with her.