I often add actions to individual animation frames (inside vs) such as sounds, toggling of conditions/values & various actions/action parts to trigger other animations etc.
I sometimes create a single animation (again in vs) & then in the first frame of the animation I use lua script & a query to determine which frame(s) should be displayed. That way saves me from having to create multiple conditions/objects for the same thing in different states instead of multiple versions.
Interaction animations have to take into consideration the scale of the character at that point in the scene. Especially animations which involve taking/using/placing items as the item needs to be correctly scale down from 100% to the same size as the item being placed/taking from that point in the scene.
One issue with animating character & object together inside of the same animation is that you need to make sure that the character/animation is correctly scaled & positioned which can be quite difficult/time consuming.
Ok in your example I would:
1. on character reach interaction point of the object, trigger the character animation.
2. during the button press animation I would add an action to the frame where the button press should trigger the glove flying out animation.
3. Same as (1) I would again add an action to the glove flying out animation which triggers the character flying back animation on the frame where the glove contacts with the character.
etc... etc... I think you get a general idea of how I approach programming animations now? Unfortunately I'm no artist & thus it would take me ages to draw up some simple diagrams.
P.S: I understood your English perfectly!