Anyone remember Wild Arms? It wasn't just a rpg with guns, the gun was somewhat central to the main storyline. The main character knows how to use the guns or ARMs (Ancient Relic Machines), and uses one to help his village fight a demon. He is subsequently exiled from his village for using the ancient banned technology. The ARMs could be upgraded, but you could only hold a certain number of bullets of each type of ammo at a time, and they took quite some time to reload. You gained two friends in the game, but you were the only one that could use the ARMS. I liked how guns were done in that game, not saying it would work in an Divinity game, just bringing it up.
I don't know if guns would work in Divity, since they've never been there before. It might seem tacked on. If they were in there, they could be like a clunky, heavy, oversized dwarven technology. Bullets would be heavy and hard to come by (similar to how Scorpion traps are). They could pack a big punch of purely physical damage (like Hell Spikes) but would be balanced out by long recuperation times (think of how long it took to reload a revolutionary war era rifle compared to how long it takes to swing a cutlass a second time).
And something that would make a bigger difference between bow vs gun, in DD at least, bows had a delay in flight, so if your target moved, your arrow would miss (nevermind rolling for to-hit, AC etc). And there's of course no way to lead your target in DD. Maybe guns would have significantly less flight delay time, so they almost always at least hit your target. Just my thoughts.
