Hi there,
I would like to work with you in getting the changes you mentioned done for sending private messages to some specific User IDs that you'll add in an input box (textarea). I have good amount of experience in using FB APIs and have worked in Javascript/Jquery for a long time, so this should be doable.
Couple of questions I had:
1. The current script that you have, is it in Javascript? And how do you run that script today?
2. For your new requirement of adding UIDs to send message to, would be better if we build a chrome extension for it. What do you think?
If we do decide to move forward on this project, we can discuss about the exact needs of the project in detail. Hope to hear back from you.