For the first question: Metallia would be fine, actually! You'd have the option for her to get sick over time if you'd like (as we're always willing to work with players about things like this), but if you'd like her to not have to worry about that, then it's an option as well.

Second: Characters will remember everything about themselves! However, they just won't remember how they got to camp or who put them there upon waking up.

Third: Absolutely! You'd have until applications open to change who you wanted to reserve, though after apps open you'd be locked into whoever you last chose to reserve.