This was a refreshing read, OP. A quick note I have on Tifa: The game does tell you how she got to Midgar after the Nibelheim incident - her trainer finds her unconscious in the reactor and takes her to Midgar since medicine is more advanced there.

Also I was surprised you didn't mention her strengths as a character due to her weakness - wanting to keep tabs on Cloud but always being too afraid to meaningfully bring up his past, being indecisive and allowing his problems to escalate...a very human shortcoming that is rarely depicted among bands of game-heroes.