(1) My bag wasn't over the weight limit, but it was heavy enough to do some damage to her head if I accidentally let go of it.

(2) FAA requires airline to ensure passengers in exit rows are capable of performing duties. It does not require them to stand in the exit row. While it is understandable that SWA finds it easier to verify eligibility at the time of seating, there is no FAA rule that requires the FA to stand in the exit row - or you would see it on every airline.

(3) Basically, it was an example of an unappreciative FA, or maybe one who was having a bad day. In either case, there is no reason to fabricate an "FAA rule"