Flights/Itinerary is set--thanks for the advice
 

Informed by thoughts from this group, all the flights, and most of the itinerary, are set. First visit to China. Welcome comments for things to do or side-destinations to visit. Also sharing some lessons learned, which are probably well-known to this group, but were new to me.

LAX-Chengdu (TFU), Sichuan Airlines NonStop, Biz. One mystery solved: In April, the LAX-TFU route changes TO nonstrop FROM direct with a "technical stop" in Hangzhou. I have no idea why it changes, but IDC. It's a bit nerdy, but I'm excited to fly the "Panda Livery" A350 with its Pantastic theme throughout, from the exterior paint to the interior design. Even the food is decorated with panda designs. 5 days in Chengdu. Plan is to eat a lot and visit pandas. Maybe a day-trip to Chongqing.
Chengdu-Dali, CZ economy. This flight is so short, no sense in paying for more than economy, IMO. Unexpectedly, every Chinese native or seasoned traveler I've spoken with thinks Dali is the best destination of the trip. 4 days of hiking, nature and tourism.
Dali to Beijing (PXX) CZ economy. The "anchor" of this trip is an event in Beijing, so that's where the bulk of my time goes, ~2 weeks, with some tourism on either side of the event. Maybe an overnighter to Xian, but not sure.
Beijing (PEK)-ICN-LAX OZ biz. Two airlines offer nonstops PEK-LAX (CA and UA) but both are nearly 2x the price. Easy layover in ICN makes this a clear decision for me. Had choice of two routings on OZ, one with 50 minute layover one with 2 hr layover. I chose the longer layover because I don't want to worry about making a tight connection. Either would probably be fine, but I chose less stress. Could've flown CZ biz for same price via PEK-HKG-LAX. Most seasoned travelers prefer CZ to OZ, but not enough to justify the extra time, IMO.

Key lessons:
1. I was very surprised at the lower costs available by booking this as two transpacific one-ways instead of same airline round trip, multi-city, or open jaw. I'd always thought round trips were more economical than one-ways, but that was completely wrong.
2. Booking SA and OZ was challenging. Website crashes, no seat assignments, etc. etc. Each ticket involved multiples calls/emails with customer service hotlines. All worked out fine but surprisingly difficult. Easiest bookings were CZ china domestic routes.
3. China domestic flights soundly beat trains (for this routing). Originally, I'd thought I'd do all domestic travel via high speed rail, but upon further investigation, that just didn't make sense. Still a bit nerdy, but I want to try the high speed trains, which leads me toward a day trip to Chongqing from Chengdu.

Thanks again for prior advice, and appreciate any additional thoughts.

Your itinerary looks solid to me.

Wrt #2, since you appear to be based in Los Angeles, I probably would have checked out a bucket shop or two before resorting to direct bookings.