A: Yes. The zombies can win, even if they Ain’t So Bad. Specifically, the Zombies Ain’t So Bad Rule says that you can still win even if zombies are disallowed on the Goal, but it says nothing about zombies being ignored on UnGoals. Just because you can win with them, doesn’t mean they might not also be able to win.
Thematically, imagine a world where zombies pose no physical threat to humans… but they have taken complete control of power. The president is a zombie, congress is all zombies, the supreme court is all zombies. Humans are not allowed to hold any positions of power, and are an oppressed minority. But hey! They’re not eating your brains!
Not so bad is not the same as good.