What I have found so far:
Select Actors and convert to Blueprint class: Actors don’t keep their scripts and collisions. Every single object needs to be “remade” again. Can be used level independent.
Grouping Actors: Groups actors, duplicating actors clutters the worldoutliner. Cannot be used outside the level.
Folder in the world outliner: Stores Actors neatly but the folder can’t be duplicated.
All these options suck! My current workflow is this: Put actors in a Folder in the worldoutliner, group them. Duplicate them, make a new folder, move the new actors inside that folder.
Duplicate the level so I can reuse the Groups and Folders.
OR: Make a blueprint class from selected actors and redo scripts and settings that I already had to do for the single actors.
I really hate working like this! Am I missing something or is this the UE4 workflow?