Honestly, I've always thought monsters exploding when you hit them with a crossbow bolt or sword is dumb.
Yeah, I ususally had those off in BG1&2. Fallout1&2 had pretty darn good stuff like that, but I suspsed that OPs problem isn't with lack of gore but overall tone. I mean we have people burn alive when killed with a fire spell and other elemental attacks - it's more grusome then anything in BG1 or 2. It's just no one takes it seriously enough to care. They can add beheadings and dismemberment and it still won't feel "crunchy".
I would be wary of going to far. Dragon Age tried very hard with persistant blood, but it made it more hilarious then immersive. While your characters probably should be covered in blood, shit and gore, you probably don't want that when you talk to random NPCs.
