What I would've preferred...
1. Frontier shotgun is fine. But should be mini crits. I saw 7 Revenge Crits built up in my shotgun. That is FREAKIN insane if you're guaranteed crits like that.
2. Have a different set of build plans linked to another wrench. Buildings can't be upgraded either, but are movable. OR if you guys are DEAD SET on keeping this movable building shit then I say this: Make it so that ONLY lvl 3 buildings can be moved, and they transform into lvl 1 buildings when rebuilt. You're still walking slower and can't attack while carrying it.
3. Perhaps have another wrench that swings a lot slower, but helps build faster, takes off sappers in one hit, and maybe causes random stun too
4 No wrangler...PERIOD.
5. Have something look like the Wrangler in the pistol slot, but it's more like a sonar that is used to make spies glow. Uses up metal while it's on.