1. Zeb is an aimless dude on a mission to destroy a big bad robot.
2. Zeb is a guy. C'mon, hear the voices!
3. Because it makes the game cooler, or maybe it fits the game's style. And It's "Why is HE fighting the army."
4. An old 1990 style robot with a rocket launcher and Bad news guns. The robot is just a big robot and nothing else.
5. The sounds are all prefab and made by Clickteam, as is the game.