Critique - Trust

You're over extending his right leg at around x55 to x86. So when he takes that first step, don't move his body up in Y so much and when he leans forward to move the chair, have him take a little step with his right leg.
His right arm is overextending towards x113 as he pushes the chair. The wrist is also not changing rotation as he pushes the chair. Take x120 for instance. His arm gets off the chair but it's still overextended and the wrist is still rotated the same way (hidden behind his forearm). So as he pushes the chair, rotate the hand screen right so that we see the hand/fingers. When he takes his hand/arm off the chair his arm will be bent and take x120 again, his hand will be down and towards the right (the chair). Act out exactly what you have in your clip right now, you'll feel how twisted your wrist is and how unnatural it is to leave it like that when you push off the chair or just let go of the chair.
Move his left knee out screen left around x86 so it doesn't point inwards, makes it less awkward.
As he puts his hand behind his back, make sure that you are also moving his shoulder back (and forward again when he points the gun at him).
The arm move when he points the gun at him is too fast. Don't move the arm/gun higher than x116. Look at x124, he's shooting at the ceiling right now. He's showing the guy who the boss is, so the gun needs to be steady on him.
When he takes the step around x120, make it read that he's taking a step forward with the up and down of the body in one nice move. Right now it looks like he's moving forward and up til x123, then the forward movement stops and he just goes down.
Rotate his right foot more screen left when he takes the step from x112 to x126 (the foot will be more forward per above critique). That way you change the pose from A to B to make it more interesting and the foot needs to be rotated especially at x 142 when he takes another step. Look at that frame, his body is almost in profile, his left leg is taking a giant step forward, but his right leg is in a very awkward pose. The knee is kinda pointing to the left but the foot is pointing "up" (screenspace, not lifted off the ground). So when he takes the previous step and have the foot plant pointing more screen left that pose at x142 will be better.
You will have to adjust the body when he takes the last step at x151, don't have him move that far because you're over stretching his right leg. You need to add a foot roll as well when he takes that step, maybe that will be enough to keep the leg from over stretching and you can keep the body translation.
Lower his body at x164, you're over extending his legs again.
Next, change his appearance, start off with at least a dark (unless he's wearing a white shirt) suit. You need to think about how he will blend it with the live action plate so that the silhouette is reading nicely.
Another thing you need to do is applying a holdout shader to the table geometry. So in Maya, create a shader called "Use Background". Apply that shader to your table cube. Now when you render it it, you'll see your guy looks like he's behind the table. You'll have to place a light where the window is and one behind him where that table light is. Give both lights a greenish tint to it so that the character fits into the scene. If you have trouble with that, I can show you in class next week.

Cheers
JD