Voting wise, the only suspcious part is not voting this round so far. The bonus is big enough we could fairly easily identify the vulture if they vote now. That's all.
As for your points about self-targetting. That's completely true. If that's what happened here I think we're in big trouble already. Your point has merit. However, the odds are in our favor based purely on when he was picked. (At the beginning of a mafia game, the odds are you'll lynch an innocent, but also that if you pick one single person to trust, they'll be innocent as well.)
However, if we made a mistake on world, that can still be fixed in a round or two if we suddenly get suspicious. If world is innocent, FG's will probably knock him off anyway, as it's not good to have "known" innocents running around who are coordinating ability usages and will never be lynched.
In the meantime, we have this round and next to kill the vulture if we can't trust him. If it turns out the vulture is an FG, it's game over after that point. Even if we're wrong about it, it's still good risk management. My targetting of you is mainly because of your suspected role and how potentially dangerous it makes you, combined with my inability to rule you out as an FG. I don't know how to prove you're safe at this point, and I think a vulture is a more immediate threat than world.
Again, I admit there is little backing this. But I can't accurately finger an FG right now, and risk management is the next best thing.