Well, Takeru's fine with being forth-walled since Shuichon and others already did it a long while ago. Relena and Yuka probably wouldn't be recognized (yay timetravel!) Nanoha, Hayate and Vivio are definitely a go to be recognizable. As is Neku.

Galen... maybe. While she probably would know Star Wars because it's Star Wars, I'm not sure if she'd know about The Force Unleashed.

And I can't even remember most of my other characters, so yeah, that's all for now.