Free look Mouse ScrollWheel and block axis control

Pretty easy to set up with a simple script to adjust vcam parameters.
Can you be a little more specific about what kind of camera movement you want?
e.g. rotate means camera aim adjustment or orbital rotation about some look-at target?
and z-position means...?

 

ok, so you're talking about orbiting around the target.
Mousewheel controls the radius. Got it.
What happens when you drag vertically? Is the camera moving in a sphere around the target, or is it describing a cylinder? Or some other shape?

 

ok. Use an ordinary vcam, with Transposer and Composer. Set the transposer Binding Mode to World.

Nothing out-of-the-box. You will need to make a custom script to manipulate the transposer's m_FollowOffset field based on your mouse input. For rotation, rotate it. For zooming, scale it. You will need to set limits on the vertical rotation, to avoid making the camera look straight up or straight down (vcams get confused when they do).

You can access it as follows:
vcam.GetCinemachineComponent<CinemachineTransposer>().m_FollowOffset = bla;