Balloons would sink at first direct big crosshair hit, don't think engi's would like a needle and thread tool XD
Though I do find it amusing the thought of making some poor fool having to climb the balloon to fix it. Duct tape anyone?
Hmm, I didn't know that about the engines, that's actually pretty cool.
My fear would be the friendly fire. Heh, literal in some cases. Flame squid would be the new munker.
Tar cloud would have to be taken out entirely, though I once discussed the idea of how hilarious it would be if players could set tar clouds on fire to either get rid of the them or cause a flash fire behind them. Ooh, but how that would be used for trolling.