Yes, this again. We have the M4(75) up and running now, so I don't imagine that it would be too hard to add this. Just something a bit more survivable to spawn up on the beaches and that can take out a tank if you get lucky, you know.
Won't be able to fire and it will be hidesouly vulnerable to anything with a cannon when its in the water, seeing as it will be even slower than the LVT's we have now (4.6 mph).
Have it be driven by the commander using the rudder keys (like you can with LVT's) and just model the tiller moving to the left when you hit the "A" key, and to the right when you hit the "D" key.
Doesn't sound like it will too hard to defend against if you're on the ball. Perhaps move your CV in close to shore a couple miles up shore from the base and land your tanks there. May increase survivability to get them up on shore before the fighting starts.