Planning stage: can you execute simultaneous non-overlapping animations on the same rig?

I have looked, but not found an answer to my following question. I apologize if this is common knowledge. If no one knows, I will probably create a test rig this weekend.

What I want to achieve: a more natural idle animation, where I have the freedom to add a new pose without turning off breathing, or even switching off breathing while posing underwater (and puffing out the cheeks).

Suppose I have the following 4 “idle” animations:

Breathing: chest and hips, 1.5 second loop, automatic (within R15)
Pose: arms, fingers and legs: various lengths, set by player (overlaps R15)
Blinking: eyelids, 2 second loop, automatic (outside of R15)
Watching: head and eyes follow a target via script, continuous (overlaps R15)

3 questions:

  1. Since they all use non-overlapping bones in the rig, can they all be running on the same rig at the same time? I don’t want breathing and blinking to be perfectly synchronized. The alternate solution is to extend the animation to hide the repetition. Obviously, using 2 smaller animations is more powerful.

If 1 is yes:
1a) I suspect this will only be possible through scripting. Any chance of a shortcut?

  1. Can an “idle” animation not tied to R15 (eg blinking) continue through an action? I don’t see why this would be an issue. R15 shouldn’t know the eyelids are there. I have no expectation this would work within R15.

  2. (BONUS!) Can a skinned mesh handle the transformations from 2 different animations (example, where the shoulder meets the arm)?