So far it looks great. I'm uploading a more complete collection of class/race/firearms. Please add these changes to your above documents when you get the chance, I balanced out the feats and clarified the classes and firearms a fair bit.
I'm interested to see what you come up with for these bio-experiments/mutants. So far I was thinking that the mutants would have a small amount of resistance to weapons do to their dry callused skin, but vulnerability to steam that causes them to lose this resistance when they take damage from a steam power.
I suggested the new damage types steam (similar to fire, but also uses pressure and pushing), metal (replaces radiant) and rust (replaces necrotic). View attachment Steam punk.doc