Hi there

Well where do i start with this one

LAX- Brisbane (BNE), Sydney (SYD) and Melbourne (MEL) are all in the same zone (just... but get someone in ticketing to confirm this) so a ticket should be accepted to any of these places. BNE has 1 a day, SYD has 2 flights a day, and MEL also has 2 but one is via AKL and is generally a bad idea. Worthy to note the A380 is operating to MEL and SYD, so some extra seats there. Also note AA don't fly here... they codeshare with QF. Only other airline that flies here is United to SYD & MEL, although this is set to change soon with the open skies agreement.

Bear in mind the QF staff in LAX are contractors, and WILL hold you until STD -15mins regardless of whether there are 1 or 200 seats available. And don't be expecting any form of upgrade from them. Even QF staff don't seem to be a fan of these guys, so just bear that in mind. (This is if you are flying out of TBIT, I think BNE flights go out of Terminal 4 though which means you will be checked in by AA staff who are a little more friendly, but I think the waiting and lack of upgrades is same same).

QF have all but given up on the Gold Coast (Coolangatta - OOL) and shifted most (if not all) flights onto their subsidiary, Jetstar - which i dare say you don't have an agreement with. Only option is Jetstar or Virgin out of SYD, or those two and Tiger out of MEL but you would have to buy a ticket. As for a train, that is a long trip my friend and it stops south of the Gold Coast - "Due to a difference in the gauge of the railway between New South Wales and Queensland there are no Interstate direct rail links to the Gold Coast. Trains depart daily from Sydney and terminate at Murwillumbah (around 30 mins south of Coolangatta)" - thanks to http://www.gold-coast.net/goldcoast/gettingthere.html. Note there is a train from SYD-BNE, and it takes 14 hours and you will pass the Gold Coast! (Google Countrylink to find the train info).

Note the train from BNE airport to Gold Coast also takes around 90minutes.

If you buy a ZED ticket BNE/LAX then no you won't be able to go BNE-SYD-LAX. You will need a seperate coupon for this. If it is a transit flight such as LAX-AKL-MEL this is sometimes OK, but even then it is recommended to have separate tickets in case of being bumped. QF allows pax to book MEL-SYD-LAX or BNE-SYD-LAX but the first flight is a seperate domestic sector, it is never a transit/same aircraft so seperate coupons are required.

I'd say loads at that time are relatively heavy, but I have had friends who have made it OK. Bare in mind there is also an SFO-SYD flight. There are some Qantas ppl on here though so i will leave that to them.....