I want my character to aim with the mouse so, arms and head must move following mouse cursor and when the character is stand still it could change its stance a bit to accommodate the arms position. I used to use skeletal systems and in this situation I would use a bone that would move both arms at once but it seems Unity animation only supports tweenings. Can this be done with this system?
On the other hand how would you setup the character to easily make it follow shooting position with head and arms without moving all elements from code? As an example, if I had bones I would have set one parent bone for arms and use it to move both at once, etc. I guess IK and constrains is the way to go.