Animations What is possible when it comes to editing animations?

I have spent a lot of time trying to modify animations in this game but am at a loss as how to get any of it to work. I have been able to replace one existing animation with another, of course, but that is about it. I am trying to create new death and flinch animations. I know that there are no tools to import new animations into the game but it seems like it might be possible to modify existing animations using the xtbl tables. I would greatly appreciate any help with any of the following:

1. Is it possible to add facial animations to any of the existing npc animations? Specifically, I would like the npc to have an expression on his face when a flinch or death animation is playing. I have noticed that a facial expression plays when performing a testicular manslaughter, but I can't see how to add that to other flinch and death animations.

2. Does any one know if you can add IK to existing animations? I have tried and failed to change an existing animations by adding ik commands. For instance, there is a death animation when you shoot someone in the groin where they take a few steps back and then collapse while grasping their crotch. I would like to use ik to make the npc's hands reach for their throat (or any other body part, for that matter) while playing this animation.

3. Does any one know how to make a second animation play as part of an animation. I have tried to get one flinch animation to play but then blend into a second animation before it completes. I have tried to create new states and actions but have not been able to do this.

4. Finally is there a way to make an animation start playing at a frame other than the first one?

Any help anyone could give with any of these questions would be greatly appreciated and would open up a whole new avenue for modding these games.
thank you in advance for your assistance.