I wouldn't be looking at trying to 'balance' the character in terms of power level (although I would suggest not straying too far from what can be found with the other characters) more than with certain advanced concepts such as that, I'd expect a more in-depth sheet, something to convince me that someone isn't simply trying to pick the most overpowered 'build' they can get away with and are instead using the concept to craft an interesting character.

I'm less concerned with balance, and more in crafting a narrative that's fun for all.