So I made the booking and straight in/out SIN>>>HKG>>>LAX>>>LAS>>>SFO>>>HKG>>>SIN. Here is a couple of questions.

I am connecting CX to AA at LAX. Would 3.5 hours be sufficient for the transit?
Do I clear immigration at LAX outbound and SFO inbound?
The LAS to SFO flight is AS. How early can I check in?
Lastly, I am assuming I need to retrieve luggage at LAX and re-check in with AA? Also, retrieve luggage at SFO and recheck in with C? Or will bags interline and BPs issued all the way?

Thanks