Some fellow travelers tell me that if you use your frequent flyer miles for a ticket you will be bumped before paying passengers. They are referring to American Airlines. Does anyone know if this is true for American or any other airline?

As far as AA goes, no. Once you're ticketed you're subject to the same rules and contract of carriage as everybody else, and if denied boarding involuntarily, eligible for the same compensation as everybody else.

Can happen to anyone if late or no seat assign on-line.FF ticket legally makes no difference.Get an advance seat assignment. Even if the airline only has a middle seat left to confirm, be sure you take it. Passengers with seat assignments are typically only bumped if they arrive late and their seat assignment is released.AA does not charge FF milers like me for seats unlike BA.com others.insuremytrip.com always wise for me saved in the Iceland Volcano.

No difference for the major U.S. airlines.

When we missed a connection in Dnever because the airport closed for a few hours due to bad weather, we found out that, on United, whre you are in the queue for gettng seats on another plane has nothng to do with where you stand n the lne, but everythng to do wth how much you paid for the ticket and what your UA status is.

There is big difference when one misses connection or when the flight is cancelled for whatever reason. Most airlines will not or really hesitate to rebook rewards on other airlines. And those who pay will get priority in getting rebooked. Definitely.

But that was not the OP's question.