Explosive Dwemer crossbow cannon things are in Skyrim... I assume gunpowder is in them.

Maybe a primitive use of gunpowder but in a world with Magic and dragons, i don't think gunpowder will do much?

that is exactly what i meant a primitive use, plus with magic and dragons being as powerful as they are it wouldnt affect the game in any way, it would just add a new play style.
Again was only a thought and probably wouldnt see the light of day, a good idea and debate

Void Salts + Iron Ingot + Dwarven Oil = Lightning pellet
Fire Salts + " " + " " = Fire Pellet
Frost Salts + " " + " " = Ice Pellet
EctoPlasm + Daedric Heart + Ebony Ingot = an alteration effect pellet....

4 Steel Ingots + 1 Dwarven Metal Ingot + Broom/wood block/ground mammoth tusk - used in forge = smooth-bore Fire Lance

There is no logical reason for firearms not to have been developed within universe. They're just not because they don't want to break the feel of the universe.