dude789 has it.
1. I'm famous, at least in my own land. - Margarete is actually
Mata Hari, though nobody recognizes her in-game, which is fair enough since you never go anywhere near where the real one actually went.
2. I'm also apparently horrifically nearsighted? Okay, probably not, but that's a conclusion that could be drawn from my performance in battle. - Shadow Hearts, unlike practically every other game with front/back row and ranged attackers, penalizes Margarete's damage while she's in the back row. Apparently those two steps forward really help her aim for the vulnerable sections.
3. At least my friends can support me when fighting to help with that little problem. - But her secret weapons, being basically magic, don't care about row. Also a reference to the fact that her associates drop grenades and bazookas and aircraft bombers from the sky for her to use.
4. And you have to be impressed at my linguistic talents. While my game doesn't really think too hard about this point, I'd estimate that I know at least three languages, quite possibly more. - Margarete's battle taunts are in both English and Japanese ("I could use some help here"), and she's flagrantly neither English nor Japanese, so there's her native language as well (Dutch in real life). Since she was sent on a mission to China, I hope for her sake she knows Chinese as well, or else she's a horrible secret agent.
5. Comic relief? Me?! I'm on a very serious mission here, I'll have you know! And it's not like you jokers are paragons of solemnity, either. - Margarete is pretty much pure comic relief. Everyone else has at least SOME serious plot to go with them, while Margarete's just ridiculous.
6. Okay, so fine, I crashed it. I'm still better with technology than everyone else around here. - She crashes the escape plane, though granted, the engine was on fire.
Unused: Was considering mentioning her flashing her underwear as she somersaults around when attacking, but thought it'd be too obvious. Also "Most of my exploits are imaginary," while true (Shadow Hearts isn't real, and it turns out that most of her claimed adventures were fake in real life), isn't actually true in the Shadow Hearts universe. So 7 was going to be "...........BANG.......BANG, BANG!" Figured that would end it.
Looks like it's an open floor.