information about animation rigging?

hi I'm trying to learn the animation rigging functions but I don't find many videos about it that explain the functions to beginners. I thought I'd ask for some information here in case there was someone kind enough to answer or give me a guide for them.

1. Is it possible to call the animation rigging function via script?
(in order to change perhaps the 0/1 weight of the constraints, or activate the function if necessary via script?)

2. How do I create an animation with the animation rigging function?
(if I create a pose for the character, if I want an animation that passes from the standard animation to the created pose what should I do ??). I would like to know what to do to implement the created movements in a new animation to be called later via the animator controller.

3. I have seen that the multi constraints function Aim creates constraints on the X, Y, Z axes but the minimum / maximum range is only one for all three axes. Can't I have a different range for each axis? (Constrain the rotation of a limb by 90 on the Y axis, by 50 on the X axis, etc.)

4. In constraints instead of a target function where a transform must be indicated, is it possible to indicate a vector by? or do you have to create a transform and possibly move it with script in the desired area?
(I would like to understand the right processing method)

I know these are newbies' questions and I hope not to disturb. I would just like to understand the mechanics. Thanks to anyone who will answer.

 

can someone give me clarification? ..