Hi, Nick83, and Welcome to FT!! I think that you'll like it here.

I've never flown WS and never been to YVR, so I can only give you some general guidance. There are others here more knowledgeable than I who will give you additional information. In many Canadian cities (e.g., YYZ), you clear US entry formalities in Canada at your departure airport and your flight is treated as a domestic flight on arrival in the U.S. My guess is that this will apply to you since you were told that your bags would be checked through. In this case, you will not touch your bags at LAX.

I wouldn't worry about what QF tells you about what WS is going to do with you and your bags, as QF will have nothing to do with it. If WS checks your bags through, that means that WS will transfer/deliver your bags directly to QF baggage handling at LAX. Since they'll already be tagged for your QF flight, they'll be treated as regular bags for a pax on that flight and loaded appropriately.

Best bet is to double check when you're checking in at YVR with respect to whether they're checking the bags all the way through. Don't tell them what QF told you, that will just confuse them.

Also, as a TA, you know to check which terminal you'll be departing from at LAX. IIRC, QF departs from the AA terminal.