dojo wrote:...I wonder if it is possible for Indigo (pehaps through this thing called the serial bridge) to do what this vera software seems to be able to do... namely listen in on the alarm control and detect open zones (doors, etc) and IR sensors....
The short answer is, YES. Based on your posts you can certainly do what you want to do. The real question is how.
Serial Bridge has been deprecated and is no longer being developed, though it is available. In any case, since it requires either a PowerPC CPU, or the Rosetta virtual machine, it will not work under Lion at all. Note that Serial Bridge would still require some, possibly significant, programming in AppleScript. All-in-all, SB is probably not a good foundation for starting new development.
The good news is that effective with Indigo 5, support for Python is closely linked into the server, both for scripting, and for custom plugin development. A plugin would allow you do do essentially the same things as you noted for Vera. Based on the information and links you have posted, if you can program in Python, you can interface to the Paradox alarm system.
To illustrate, there are currently 3 alarm system plugins available for Indigo 5: Honeywell/Ademco, DSC and GE Caddix. One or more of those might serve as a good base for a Paradox plugin.
On the other hand, if you do not program, you may have a problem. You'd need to find someone with the programming skills and access to the hardware. Since the Paradox systems are fairly rare, that might not be easy - as evidenced on the Homeseer link you posted.
Should you decide to take a stab at writing a plugin I am sure you will get lots of support here on the forums from other users and from Matt and Jay. You might also want to take a look at the Indigo documentation web site
Good luck and post back if you need any help.