I see people have continued to offer great advice while I was busy for work the last few days.

Regarding Orange Line - it is a BRT that runs mostly on dedicated right or way (it was an abandoned railroad track). It definitely makes working in Woodland Hills and living in North Hollywood possible. In fact, you'd be crazy to not use the Orange line for commute to work if those are the locations you end up in.

Regarding frequent flyer miles, I think the only real feasible one for you is AA. The reason being that Qantas is the only one that offers daily flights to MEL from LAX... I'd imagine you are not that fond of changing planes at SYD. I know from experience that it involves a long bus ride from the international to domestic terminal. Sign up for the AA program and any flights you can earn miles and status on the Qantas (and other OneWorld carrier) flights.

Regarding credit checks - this is a real obstacle. Most expats I know have their employer set them up with temporary housing, usually for the first 6 months or so. Use the 6 month period to build up your credit... get the utility going under your name and sign up for credit cards (you may need to get secured credit card - you put a deposit at a bank, say $5000 and they give a card with credit limit of $5000). There are long term stay apartments that are fairly close to either Beverly Hills of Woodland Hills so you will want to talk with your HR department about relocation benefits. And if your company is large enough, they will probably be willing to co-sign a lease or help you put a large deposit down when you are ready to move out of the temporary housing.