ok, I only made some tiny changes. As I can't say what your goals might be, this surely is no complete solution (I ignored the Street scene at all) - but it should get you started!
Running this altered version should show you the room scene with five Mollys which you can select by clicking. By clicking into the scene, the selected Molly will walk there. http://wme.jerrot.de/support/multipleactors.zip
These are my changes:scripts/scene.script
I just changed that back to the original version of the demo, your changes were not needed there.actors/molly/molly.script
All I do in the "LeftClick" event is setting the global variable "actor" to "this".
So on LeftClick, the current actor will change. Moving the current actor is handled by the original scene.script already.
I also set the Game.MainObject to the current actor, so that scene scrolling will work on the selected Molly/dog.scripts/game.script
I just commented out the creation of Molly here, because I create all the dogs/mollys in the scene_init.script of the Room scene.scenes/room/scr/scene_init.script
This is, where all the "magic" actually happens. I deleted all unnecessary stuff for this demo (like the old guy, hints, etc) to shorten the file for easier understanding of my changes. Here I create 5 dogs/Mollys in a for-loop on-the-fly and assign them a position in the room. After that, I simply assign the first dog to be the current "actor" (and also the Game.MainObject). Where to go from here?
I made the "dogs" variable global to be able to address dogs from other scripts, although this is not needed for this demo.
I don't know if you want to use those dogs in different scenes, so after all it might be more useful for you to load the actors in the game.script and not in this specific scene_init.script. In this case, you could use that global "dogs" variable and just iterate over them (with a for-loop, the same way I created the dogs) to assign them particular positions, etc. in every scene_init.script where you want to have them.
And that's it, hope it helps.