1. As I pointed out in the previous thread, the extent of damage Vargas does to Terra is blowing her out of the field of combat. She is completely unharmed. This does not speak particularly highly of his power. It is not so much that Terra is incapable of defeating Vargas as that the AI won't let her (and if memory serves, if she is levelled up enough at that point in the game, which is admittedly highly unlikely due to the fact that the Lethe river exploit occurs after that fight, she actually can).
The game notes that the soldiers she fries are "fifty of the Empire's best soldiers", for whatever that's worth. The Imperial soldiers the party fights aren't particularly strong, but they're also mostly grunts, so they can't really be taken as indicative of the strength of the Empire's best soldiers.
2. Humbaba blows two party members away, using exactly the kind of attack Vargas uses. This can include Sabin if he is included in the party. Guess who he can't blow away? Terra.
3. Then you are disregarding basically all of Kefka's characterisation. Not to mention that Kefka clearly runs away so he can poison Doma, not because he is afraid of the party.
5. Right, I missed that somehow.
6. >implying that speed stats mean a goddamn thing in a cage match, or that a four-point speed difference can't have been made up through Esper stat bonuses. In an actual cage match Terra would slice the Ultima Weapon through him while he was trying to suplex her. And how is it hypocritical to play to one's strengths? Terra has swordsmanship training. Sabin does not. That leaves him unable to wield the strongest weapons of the game. If we're evaluating characters for their actual strengths in combat, not allowing them to play to their strengths is stupid.