Your outbound sounds solid. Though from my experience, it doesn't matter too much when you sleep on LAX - PEK as you'll be exhausted from all the travel when you get off in BKK (PEK - BKK is only 200nm shorter than as IAD - LAX for comparison sake). Just don't sleep on the BKK flight.

Eastbound I would aim to eat the lunch / dinner meal on PEK - LAX and then try your best to sleep for as long as possible and then eat the breakfast before landing. That way the 11am arrival into LAX will seem accurate to your body. After that it's key you stay up and try and go to bed at a normal hour that night.