Text sharing between MacBook and iPad

Situation : to record voice over, we need the director, the sound technician and the actor to share the same text. We need the actor to be able to write some notes on the text (pause, pronunciation, etc.). Those notes don't need to be saved anywhere. We also need the actor and the sound technician to be able to see any changes the director would make to the text. It would be best if only the director could actually edit the text (in case the actor messes up the text while writing notes).

The director would work on an iMac, the sound technican would work on a MacPro and the actor would work with an iPad.

Or should we process ? Using iCloud and Microsoft Word ? Using Google Drive ? There must be a very simple way to do this, but I am just not familiar with it...

Feel free to ask any questions if the situation is not clear. (Technician would run OS 10.8.5, director, probably 10.9 or 10.10 and the actor would probably run iOS 8.3 on iPad 3).