I highly disagree with your problems.
-First of all: Its a fixed wheeled unit. I don't know where you find the logic that wheels have to be able to pivot in order to turn. I drive skid loaders and many other fixed wheeled vehicles and they turn more effectively than a normal car. The only reason we don't use this on cars is the amount of wear is greater and it requires hydraulics (A low speed, fuel hungry system).
-Second: The use of four ammo box's does make it useable for transporting of ammo and other supply's. For example say that your squad is scouting. They have access to a supply of resources without the need to waste a guy on standby, and the detection of a load car or truck.
-Third: This was a newly added system. Bugs are bugs and will be fixed. I also agree with Scarecrow. But a stretcher would take up more room and not offer the practical use of transportation of a normal unit.