Yes 4 sectors at 60 points a throw. You would earn 180 if any of the sectors were over 2000 miles. But they are not and you won't.

If the LAS-DFW-ATL is one flight number then only 1 set of TP's but I suspect this not the case.

I seriously doubt you would be on a 3 class service on those routes. The only 3 class routes I know of are some of the transcons. Only some of the 767's are 3 class (762) with the others being the more ususal 2 class config (763).

I have not kept up with all the booking codes on AA and can't really answer your question about the P code.