It's 2 by land as far as I know. Ive had multiple stamped by air

I did tourist visa for my gf, she is Filipino and works in BKk. We needed to provide so many documents it wasn't funny. Proof of relationship, proof of her own money, Facebook chat, photos of us together, passport showing stamps of my visits, letter from my employer stating length of employment and salary, 6 months of my bank statements, my lease, her work permit, letter from her employer granting time off to travel.

As far as I'm aware there is no "short stay" visas, it will either be approved for 3,6 or 12 months

Vfs don't determine visa approval or not. Whole process is tracked and you can see exactly when documents arrive at Australian embassy

Yes one single desk

We went through last week. You need to check in as it's moved inside and next to passport control. My gf paid 1200 and didn't need photo or any copies. Process took about 15 minutes all up