6. Supplies are both unlimited and limited. Much like I mentioned with the Omega Man, supplies tend to be easy to come by. However, this limitless bounty also goes in reverse for specialized supplies or for supplies that are not easy to get to. For example, Andy, despite his vast wealth of weaponry, suffers the pangs of starvation. In games like Mightnight, the OGL game by Fantasy Flight Games, the setting relies on the weather and the lack of supplies to help wear down the characters. That can be true in a zombie based campaign just as well. Magic hasn't gone away, it's just all of the specialized components to use it are increibldy difficult to find. Clerics might still be able to commune with the gods, but all the sanctified symbols are gone and all the holy water is inert from lack of maintenance.
7.Direct confrtonation is hopeless. Even with minion status, the whole fear of the zombie isn't the lone zombie. It's the horde. It's the endless wave. It's the withering army. Any direct confrontation with the zombies should rely on the zombies using mass and teamwork, not necessarily cordinated but waves of them, to pull down their enemies. Grappling rules might make for an interesting twist to get characters pulled to the ground, as might disarm attempts disguised as weapons getting lodged in bone.
Dawn of the Dead has some solid action sequences, some character growth, and some characters that you love to hate. Those looking to expand their zombie lore could do worse then to check it out.