Thanks socal, I believe that answers our questions. I believe that for short-haul around the midwest that it makes much more sense for Elites to credit flights to their TWA account.
The one item outstanding is that I believe if you credit to AA, every 10,000 miles or so (flight miles I believe) you get 4 upgrade credits that you can turn back in for 10,000 miles. This would affect the total mile calculation. But for the short midwest flights, perhaps not so much. I was considering a mile-run to Japan on the sale fare and in that case you would get the 4 upgrade credits which could become 10,000 miles.
Time to fly!!
Also, don't miss the $410 Hawaii fares. Lots of miles there.