You left out the Legacy chocobo, which is tied to legacy membership along with the subscription and the option to put your name in the credits. But you're correct about the tattoo only requiring that the character existed before 2.0.
Sort of interesting, given that the opening cutscene implies that characters sent forward in time (who would have that tattoo) also had a chocobo with that same mark on their beak, while that isn't actually the case in the game itself. (Non legacy members on their 1.0 characters not having the legacy chocobo/chocobo with the tattoo on its beak)