To me, the compromise can't be in the form of too many additional rules, or flaws that interfere with fun. Like any other explosive resource (see spells), if the damage it deals compensates for the time and effort (including price) required to use it, fairness and balance ought to be apparent to the players without the distractions.
You don't have to use the mechanic.
Goblins could just steal gunpowder horns as well.For me, part of the fun is trying to use rules to the advantage of whatever I'm roleplaying. This goes for NPC's and monsters too.
When I played chess I was fond of castling.
edit:Actually I would bring the rook out of the corner to take a piece that was threatening the king, after not moving the rook all game. I thought till now that was castling.
http://en.wikipedia.org/wiki/Castling