I am getting better with the RTW rules, but I just want to make sure that my understanding of the following is correct:

I purchased an AONE3 ex-BKK. When issued, I utilized only 5 NA segments.

Am I correct that, by paying a $75 reissue fee, I could BOTH add a 6th NA A-class segment AND purchase up to two additional NA segments in any of A, D or L?

Am I also correct that the one transcon non-stop rule applies even if I purchase additional segments?

And finally, and I correct that, since I am already going to use my transcon non-stop with one of my A segments, it makes sense to purchase the add-ons in D, since an A seat and a D seat is the same on all AA flights except 3-class transcons and a couple of the 777 flights through MIA? (And, if this is the case, is the A and D inventory always the same on AA domestic flights, other than the 3-class flights?)