If you have not looked at the full manual yet.
http://www.authinx.com/manuals/X10/SC1200.pdf1st: All the older sensors and remotes will work with the SC1200 Console.
2nd: SC1200 as you may have read is not as RF sensitive. You may have to test it. I think it will be close enough.
3rd: The answer delay {not Rings} by default is 30 seconds. Can be set lower. If set lower than the five ring time.
It will answer every time. The manual indicates that you can still send the PIN access number and wait until the answering machine
finishes recording. Then the SC1200 should respond. I have never tested this method so I don't know how valid it is.