How to Create Custom Camera Motion Script when in Editor Mode?

I'm new, so might be missing something. IMO, one thing really missing from Unity's Editor Camera Motion capability is the ability to "rotate around the focus point (or object)". Just as "F" takes you to the focus Object, from there it would be nice if "Ctrl/Cmd + RMB" or CMB, would then Rotate you around that focus Point.

If your mouse is overtop terrain, it should rotate around the focal point on the terrain, defined by your current mouse location.

This form of motion makes it 1000% easier to maintain your focal point -- get closer, and then to change your "view angle" of your current focal point.

Does Unity allow us to replace the current Editor Camera Controller/Motion script? (so we can make it behave exactly how we want, per project)

 

Did you read the docs?

https://docs.unity3d.com/Manual/SceneViewNavigation.html

 

Thank you! Reading those docs now - so I won't ask (too many) more stupid questions.