I would also favor removing aggravated damage save for sunlight and fire. I would include True Faith in that category as well. Let claws and teeth do lethal damage.

Fortitude would probably need to be adjusted. Maybe just let it soak lethal damage automatically, like Potence. I realize that this would make a character with Fortitude 5 extremely difficult to damage in a fight - but compare it to other Disciplines at level five and it’s honestly not that overpowered even giving automatic successes.