Hey Mike, thanks a lot for the information.
2) That answers my question... I was thinking along the lines of ArcGIS Server in which you can register a data store and then the data did not have to be stored/hosted on the ArcGIS server. So sounds like this is a no.
3) So If we subscribe with a 5 user subscription, can only 5 people register (be invited) to our organizations account? If a 6th person were to try would they get denied? Or can say 10 people register, but only 5 can actually access it at the same time?
Thanks again for all the help!