AA is at a big disadvantage when it comes to TATL and TPAC flights because it doesn't fly its own metal to any of the cities you posted and it doesn't have ATI or JV with BA. This is in contrast with UA, who has ATI with various Star Alliance partners and DL, who has ATI with various Skyteam partners. By not having ATI with BA, AA isn't able to offer a through fare from MIA to the final destination, such as VIE or EDI. AA can, in essence, only sell you a fare to a place like LHR and then this would be combined with a BA fare from LHR to the final city. The sum of two separate fares is almost always going to be higher than one "through" fare.

I think that if you were to check cities that AA flies its own planes to, you would find that it's not at all uncompetitive. For example, for the dates you provided for the MIA-TXL flight, I did a search on orbitz for MIA-CDG, because AA flies to CDG. The result is that AA is THE cheapest option, AND it's a nonstop flight both ways. Coincidence? I think not.

AA is fully aware that it is uncompetitive in many cases. That's why it has been trying for a decade to get ATI with BA. I fully expect that once ATI is fully implemented (as it will be a little later this year), you are going to find that AA will be competitive with other airlines and you will no longer find that it is higher priced than other airlines.

And by the way, I think that the same principle applies to the TPAC flights. The destination cities you provided are ones where AA does not fly its own planes, whereas DL and UA do. AA has submitted an application for ATI with JL and I also believe that once/if approved, AA will become much more competitive across the Pacific.