You need to select a target for the main.

Run the keymap, FTL Assist Me.
You can have a hotkey for this keymap.

And then make an Interact With Target Keymap.
Set a key in wow which is IWT on all the toons.
Then make a keymap in IS Boxer, using that hotkey to activate it.
And have it send the hotkey to all the windows.

Also, enable "Click to Move" in mouse options in wow, slaves for sure, all of them if you don't find click annoying on the main.