The Cavalry musket, that thing seems to deal more damage then a sword, I've seen it bring down heavy horses with full health. That thing is insane.
Yes, and therefore it wouldn't unbalance the classes as you pretty much just proved yourself. 
Oh, but It would. My point is Skirmishers Vs Cav. As of right now, Cavalry is at Great disadvantage at range, and Skirmishers is at great disadvantage in Melee, as it should be. Bayonets and Cav muskets balances Melee between the two types, but not the ranged balance. The Range of the Cavalry musket in Melee mode will make live sour for all Sword Cavalry, and should Jaegers have acess to those, Hussars should have acess to firearms, As they historicly did use.