Rotate Particlesystem with Leapmotion

I made a SubUV particle system which I would like to rotate with the use of a Leap Motion.

Basic Idea: A static LeapMotion Hands Character must be able to ‘stir’ a particle system which is in front of it.
Think of the particle system as a sort of soup with ingredients, where the SubUV particles are the ingredients floating around. When ‘stirred’ the whole Particle system needs to rotate along it’s Z axis.

Ultimately I need to update the SubUV texture png realtime during gameplay (png will be generated an updated by another program) but first I would like to get the particle system rotate through the Leapmotion as a ‘proof of concept’.

Starting point:
As a first time user I was surprised how quick I got a SubUV Particle-system up and running and adding the LeapMotion Hands character.
I did this following the SubUV Particle turorial which I found here: A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums

Then it got complicated really fast:
I found this as a possible answer for rotating the particle system: How do I make a particle system move and rotate? - FX - Unreal Engine Forums

So I created that blueprint actor, but I can’t get a CentralPivot variable nor do I understand how to do this parenting with the LeapMotion blueprint and he rotating Actor I created.

Instead of the timeline to alter the Z-Axis I put a Leap Right Palm Yaw and a Print String in between so I would be able to see the values from the Leap and adjust the scale (see screenshot).

Is there somebody who can explain me (step by step) how to connect LeapMotion to the Rotation Z axis of the particle system?
I’ve read, searched and done a lot of toturials/forum posts who in someway connect with my question/problem, but none with a result so far.
I asked friends and people around me who I knew create games, but the all directed me to do it in cough Unity for it’s simplicity (they say).

So before I’ll switch the enviroment to create this straight foreward idea I wanted to give the Unreal community a shot as a last resort.

I zipped the project file in case it might help: Dropbox - Error 40Mb (Unreal Engine 4.18.1)