I don't take credit for this, it's directly from Sshannon's down load. "with other fixed stations only". So what it isn't is a base station.
You are right about Murs being used for alarms, gate and such (I often hear "Alert Zone one" on Murs from a nursing facility near by), and yes 15 watts may seem high for such a thing. I used that as an example. The definition and the rules for GMRS seem clear though. Granted they don't include an example, it just says what you can and can't do. No more no less. For me that's enough.