qf029 - did exactly this in November - took the A380 from Melbourne, landed at LAX at 6ish, was then on the 9am flight to SFO. Had NO problems at all - even with transferring terminals (next door to each other). Was worried about the small time between - and the fact that we were travelling on Thanksgiving and the usual reports of extreme slowness with Immigration/Homeland Security- but we made it easily, even with time available in the AA lounge. So your 4 hrs will give you a lot of time in the lounge if you have access.
I was on an paid RTW ticket - no problems. Partner was on a points RTW save for the USA legs - so had own PRN for continental USA legs. There was no problems with this at all.
Regarding baggage, yes you do have to escort the bagge in LAX round to the transfer desk - suggest that as, I have been now told, each AA LAX-SFO flight is codeshare (though doesn't always show as such), it would have been a lot quicker when we flew if we'd had a QF flight number in terms of how many people were at the QF interline line as opposed to the AA one.
Do any of you have status with the OneWorld alliance, and what class r u flying LAX-SFO? I simply had the two bags (i.e. one each) under my name - given Platinum status and that my J ticket upgraded to AA First, no issue.