How to rotate pseudo 'world' around origin? (similar to Kerbal Space Program)

Hi All! I've been trying to work this one out for quite some time now by myself, but have only got half way and am stuck!

I'm attempting to recreate the way Kerbal Space Program handles their world, where the player is stationary at origin 0:0:0 and the 'world' moves and rotates around the player.

The moving part is easy as, I have a GameObject holding the 'world' with all the other objects child to it. The player is in it's own GameObject - not a child of the 'world'. So knowing this, moving the world is easy as.

However I'm having problems with rotation for an auto-pilot type mechanic. I understand what I need is the Transform.RotateTowards() method, this works flawlessly - however due to the auto-pilot, it needs to stop rotating when the target GameObject (vector to) Player aligns with Vector3.forward. I can successfully do this rotating on a single axis, using the dot product between the two vectors, however when trying to implement all three axes, the world goes into a circular loop :\

I'm guessing some trigonometry is in order however I am not skilled enough to get the answer myself and have finally submitted and have come here for help!

See the image here for a visual idea of what I am trying to achieve.

And here using some debug lines showing the vectors from Vector3.forward (player's forward perspective) and player to target object. (I know the answer lay within the angle of this!!!)

I'm really looking forward to the solution on this, I've spent waaaaay too long on something that appears to be very simple! :)

Thanks! Nathan.