>doesn't instantly fuck everything up from second 0
well he's getting better. all he really needs to do is leave the country until around the time he first meets filo > back up naofumi when he gets back using the fact that he was out of the country as a reasonable excuse for not defending him > boom raphtalia is with naofumi, filo shows up and motoyasu isn't hated by both naofumi and filo (naofumi seems fairly amicable with people that don't automatically assume he's an evil rapist. go figure). also considering that that first debacle is what turned him into the cynical guy it all kinda fits everything back into place for everything not to go sideways from the beginning.
This is on 2 (let's face it, likely) assumptions that bitch will use any of the heroes to do what she originally did and the heroes she tricks are going to blindly believe her.