So my partner and I have 2 business class tickets booked LAX to SYD in U, since they were mileage tickets using AA miles. I have three questions:

We are actually booked on flight 108, which doesn't have first class-- are the ticket agents at the lounge at LAX authorized to change our flight number provided there is space and we stay in the same cabin?

Second question, I realize that we can't use miles to upgrade unless inventory allows, and had it allowed, we would have just booked first from the start. However, sometimes they have those counter specials where they say like "$1,000 to upgrade from Business to First"-- do they ever do such things on Qantas? And if so, do they discriminate against mileage tickets at that time for upgrade purposes?

Lastly, is there a "human element" we can appeal to at the lounge at LAX to explain how we've always wanted to take the first class flight, but have never been able... that we wouldn't mind flying through MEL or delaying a day, etc-- do these kinds of stories ever work? Do the ticket agents have the authority to override the system and grant requests if they feel like it. Again, I'm happy to pay something or use more miles... but I really don't know what to expect.

Just incase it makes a difference, I am ExecPlat on AA, oneworld Emerald, and my partner is Gold/Ruby. Thanks!