If you have not found it yet, Smarthome has a forum specific to Insteon. Lots of good information over there. I have found that understanding how native Insteon devices work together is a big help in understanding what EZSrve is doing. Insteon architecture has been around long before devices like EZSrve became available. Knowing how the Insteon hardware works with Groups and Links and link databases makes understanding how EZSrve is using those functions and features easier to understand. If you get hung up on something, someone on one of the forums is always more than willing to help.
The link to the Smarthome forum http://www.techmall.com/default.asp