Regarding keys on every bone in a Smart Bone Action:
This error probably happens to everybody at one time or another (an artist where I work ran into it earlier this week.) Fortunately, it's avoidable; you just need to be aware of how it can happen.
For example, one way this happens to me is when I used Freeze Pose when I meant to use Freeze Selected. Or maybe I accidentally bumped the rig while all the bones were selected...this can happen when I'm zoomed in and don't notice I have other bones selected.
The fix is to select all the bones that are not supposed to have the keyframes and delete the red 'Selected' channels. Tip: Sometimes it's quicker to select the bones that are supposed to have keyframes (like the Smart Bone Dial,) and then choose Select Inverse.
Finding which Actions contain the unwanted keys can be trickier when I have a lot of actions in my rig. To do this, I need to double-click on each action and work my way down the Actions list to see which ones have the unwanted keyframes. This gets tedious when there are hundreds of actions associated with the character rig.
IMO, it's best to periodically check the rig during the rigging process, so I can catch and fix such errors as soon as possible. Oh, and pay attention so I don't make the mistake in the first place.
Hope this helps.
