Another possibility would be to apply the free maneuvers only to critical hits, so that as long as you have the "improved" feat of a maneuver whenever you confirm a crit you choose whether or not you get the extra damage or an auto success on the maneuver. Obviously some maneuvers wont lend themselves to being triggered by certain attacks, but a bit of common sense from the GM and the players should forestall problems here.
You could even put a critical feat in the crit focus chain that lets you get your extra damage and the maneuver.
This I feel would be a way to get more of that brutal and dynamic feel that you wish, without devaluing (psychologically not mechanically) maneuvers by overuse.
