Hi y'all, it's been a minute! I would like to ask for feedback on a trip that I planned for my in-laws (late 60s, but fit -- both have always hiked), accompanied by their children (late 20s). They'll do some hiking, but nothing too strenuous or very long. So, trip-wise, be it driving or sightseeing, the pace can not be too great, though things can be pushed at certain points.

The idea is for a 16-day trip through California, Arizona and Utah, hitting the major National Parks and other landmarks and places along the way (must sees: Grand Canyon, Yosemite and PCH). We decided to avoid Jun-Aug because of crowds and heat. Between May or September, I think May makes more sense as Spring is at full steam (e.g. one can see Yosemite falls) and there's more daylight, even if temperatures in some places are a bit high. So, we're pointing towards starting the trip on 10 May.

Current Plan (~ means somewhere around that area)
Day See/Do Sleep in Driving (h)
1 Land in LA LA 1
2 Movie studio, Hollywood boulevard Lake Havasu City 5
3 Oatman, Arizona State Route 66 Flagstaff 4.5
4 Montezuma Castle NM, Sedona Flagstaff 2.5
5 Grand Canyon Grand Canyon 2
6 Desert View Drive, Horseshoe Bend, Bryce St George, UT 7
7 Zion NP St George, UT 2
8 (Maybe Zion NP), Las Vegas Las Vegas 3
9 Death Valley NP ~Death Valley 2.5
10 Sequoia NP ~Sequoia NP 7
11 Yosemite NP ~Yosemite NP 4
12 Yosemite NP ~Yosemite NP 2
13 San Francisco ~San Francisco 4
14 PCH ~San Luis Obispo 6
15 PCH, Santa Barbara ~Santa Monica 4
16 Fly off. 1

I would appreciate comments and suggestions. For example, road X might be closed, or rather than staying in Y, stay in Z.

A couple of final notes:
- I'm aware that the PCH is currently closed between Esalen Institute and Lucia Lodge, so we'll see.
- I would highly value suggestions of stops along the way, especially, but not only, for long driving stretches (orange in table above).

Thank you!