I think I know the answer to this, but wanting to see if I'm missing anything. If I book through either the chase or AMEX travel portals, I get 5x points with either. As I'm thinking about it, I would then also get points via American, correct - as in, the same number of points? And if I were to use an AA card, I'd get the same number of AA points whether I booked the flight through the Chase portal or directly with AA, correct?

The only downside I can think of is the trip credit system and that being cumbersome - specifically, if I book through the Chase portal, then cancel, I would have a trip credit living within the Chase system rather than the AA system. I can't see any specific downside to this other than flexibility of then needing to use that credit via Chase.

Last I checked, AA charges to move a "group travel" reservation into your own name, and therefore changeable within the AA system. Does this affect either upgrades, free same day changes, etc?