Changing Variables on Actors in editor (Not in PIE)

Hello everyone i am thinking of the posebilaty of prefabs (a group of actors).

I know its planned on the Roadmap but am beeing a bit bold and am going to try to make one.
Am getting familiar with the gameplay framework but have not tutched anythign related to editor/ manipulating actors present in the scene (Not running Play in Editor).

So am hoping anyone could give me some pointers on where to get started, some pointers on what docs to start?
How whould i be able to e.g: Change the Z value of the location when a actor is placed in the scene?
Or detect if its overlaping with a other actor or component?

I think it be realy fun to be able to share something like that with everyone but am unsure where to start.

Anyone have a idea on how this can be done?