Flying direct between the USA and Cuba is easier than between Taiwan and China at the moment. The restriction against direct sea links was just lifted but I wouldn't expect air links to be lifted anytime soon
As for CLT's routing, this is really a tough one. I think you will need to change the order of your cities that you will visit.
The best I can come up with is to fly
SQ 029 from LAX to TPE daily at around midnight
SQ XXX from TPE to SIN (mainly daily options)
SQ 806 from SIN to SHA daily at 10.20am
UA 858 from PVG to SFO x24 at 6:45pm
or
UA 890 from PVG to NRT daily at 11.10am
OR
you can fly SQ r/t USA-SIN with stopovers in TPE and HKG. Then from HKG you can buy a separate DragonAir or China Eastern ticket to Shanghai... Actually, this may work out to be the most economical...
[This message has been edited by fallinasleep (edited 01-12-2001).]