Hmm... Not bad for starters.
I think the first one needs more anticipation(bring the minifig back farther at the beginning of the swing) and more following through (moving the hand forward more at the end). The more force in the movement, the more anticipation (bringing the hand back before the hit) and following through (continuation of movement after contact) you need. In your test, the amount of force put into swinging the fan and the amount of force put into the guy falling over looks unequal. If you wanted just a slap, pivot the slapee on his feet and move his head to the side, but don't make him fall over.
On the second one, I think it needs some inertia; in this case it would be the torso following the punch. When he anticipates, his torso should be moved back. When he's swinging his arm forward, his torso should be moved forward. This also helps with conveying the illusion of force in a movement.
Not literally dead, just no longer interested in Lego or animation.