The weapons would only be overpowered if allowed to be by the scripter.
Weapon_Gun is overpowered if you adjust the damage value to 100.
I'm not really sure about the vehicles, since we have mechs, planes and tanks already, but the weapons would probably be worthwhile if someone had the time and wanted to make them.
As for the AI, it's already been done, and the amount of work which would go into animation would probably we wasted when barely anyone downloads the addon.