@GarfieldTehKat Same here - they're just excellent for those times when you want to switch your brain off. I still live in fear of those bots though.
I'd need to double check (speaking of switching brains off) but I think BF4 had Frostbite 3 so destruction should be possible. Some mounted MGs would be nice if they got added and, like you mentioned, it'd be a really good map for Irish and Dozer. Actually Casper should do OK on the outside area or flying the drone through the inside too.
I can see why some people think of COD with a map like Locker but I don't see it myself. I also think that, like with Metro 2.0, it'd work alright for Breakthrough as well as Conquest.
The biggest issue in my mind, again similar to you, would be how XP would be handled. It'd probably need full progression to encourage people to play.