Go into your keyboard bindings on your clone instances of WoW remove the WASD keys and whatever key you have binded for Auto-Run (Numlocks by default) and just leave them binded on your main.

This way your main will cotrol your characters with /follow and they will not have movement keys bound to make them do their own thing.

Right now there isn't a way to dupe mouse clicks.

Also you can set up the Do-Not-Pass list for whatever key cloning software you are using.