I doubt these will be full fare economy, likely just Main cabin - just a step up from the most basic fares. She will have hotel and car rental expenses though, so I like the spend going towards status. This is a significant advantage of AA/AS over say Delta & United in my mind. Which would you recommend crediting to between AA and AS for coach travel (nonstop)?

She has a reasonable number of Amex MR and Chase UR accumulated ("reasonable" for a non Flyertalker lol, just a young under-25 year old starting some business-expensed travel), and I would've preferred spend on those cards as being most flexible; but will look into the Citi AA card to see what the advantages are.

Nonstop flights, IMHO, take precedence over travel hacking segments. Will keep it simple, she will likely fly out of LAX - but I wonder if it's worth considering ONT/SNA (if possible) for ease of airport experience. She is still figuring out where exactly she wants to stay, it's a remote job that requires West Coast travel (mixed in with some potentially longer flights towards the East Coast perhaps down the road). It's a pretty exciting opportunity for someone young who likes to travel, she is embracing the idea and I am trying to maximize the travel part for her, within reason.