Dude, if the save system bothers you that much and you don't care about the story and just want to kill countless zombies, get Dead Rising 2: Off the Record. It has a Sandbox mode which you can access right from the start and the whole world is open to you. Obviously you won't be able to follow the story, but you can kill zombies to your heart's content and level up your character and unlock new skills and so on. Once your character is nice and strong you can start the story mode and it won't be as frustrating as it can be with a low level character.
