I think Valve's point of this whole new interface with new weapons wasn't to give any player an unfair advantage, but to give everyone who unlocks it more options. For example, on a website I read that the Blutsager doesn't crit of course, but is great for using when running away from a battle to regain health quicker, hence, more options. It helps change your strategy, maybe so people don't get bored with the game and go buy a new FPS that just came out.
Anyways, back to the new weapons ideas, I think the pyro's flamethrower should be able to burn the ground and everything around it, but take crit away. I have no clue what to do for the shotgun, and I don't know what Valve will do for it since the Soldier, Pyro, Heavy, and Engineer all have it.