Yes, the smaller city start can be less expensive, but I thought it was usually for one way fares.
I watch USA to Asia all the time, though Sometimes only SkyTeam. LAX is the cheapest gateway by far on ST.
Philippine Air has some cheap HKG-LAX RT. for $1900 in J. I did not check LAX_HKG
Yes, I wouls also wait. I bought a KE J months in advance and watched the price never change until 2 weeks before departure.