1. No idea. I'm hoping to get to Whitney in 2 weeks though.
2. The drive up 150 and 33 to Maricopa is nice. After that, it's all the same. You can also turn off 33 earlier, once you pass the mountains, through Frazier Park, cross over I-5 to 138 to Lancaster. I don't know it's worth an hour of extra driving. If you were from someplace besides Colorado, maybe.

Saving some time, you could take the 126 out of Ventura, and when you hit Santa Clarita, turn north through Green Valley via SanFrancisquito Canyon Rd. About the same time as the fastest freeway route. You can't avoid high deserts. lol.