Your creative problem-solving skills blow me away.
For those who've never tried to create machinima videos, it may not be possible to comprehend the staggering feats you accomplished. I wouldn't know which animation is harder to do than another (walking, jumping, opening a car door, twirling a hat on a fingertip). But this blows me away:

.....when I tried to animate the twirling hat, I could not, for the life of me, get the correct physics response from a logical sequence of cause and effect. I won’t bore you with all the details, but the short version is that I finally just engineered the thing in reverse. Instead of making the hat respond to the rotation of the hand, I made the hand follow the rotation of the hat. I did this by animating a cylinder, which is invisible in the rendered scene. I put the cylinder into a constant state of rotation using keyframes, then I used it as the kinematic “engine” that drives the hat. I assigned the hat a dynamic physics state and played with pivot points and axis locks until I got the right effect. Then I attached the hand to the hat, and while I had to get extremely creative with dummy props to prevent the wrist from making unnatural 360 degree rotations, I did manage to come up with a fairly convincing animation.