Yet another silly thread where the correct answer is self-evident, it likely that OP simply misread the advice he was given, and has not returned to provide the information he actually received. Particularly because if someone told him that a passport is required for a USN to enter Puerto Rico from the mainland US, that someone would be wrong.

The thread has then devolved into a question of whether one ought to obtain a visa for countries one may overfly. The answer to that is the same as to OP's question: No.