Making attached component editable

No doubt there are some routines in the engine for doing that kind of property and subobject copying, but I’m afraid I’ve not tried anything similar myself so can’t help you there.

I’d be wary of going that route though - you open up a world of pain whenever Epic make any changes to the engine’s AStaticMeshActor class.
If I’m understanding right that all you really need to add is editor interaction functionality and not any custom data or logic to the actors, you really want to avoid making any changes to the makeup of the actors in the level. Your best bet would be to make an editor extension that just provided a new tool window for manipulating the selected actor (if compatible). But yeah, anything like that is quite an effort, especially the first time.