There are a lot of good reasons for allowing the elk Rules to access the thermostat variables even though a thermoistat is not attached.
First, the Elk has a real limitation in the number of custom settings available - 20. I've used 19 of those already and haven't even implemented thermostats yet. There are 16 thermostats available, with lots of usefull values that could be used in a variaty of applications like pool heaters, virtual thermostats where a house is divided into zones and the HVAC is controlled via Elk Relays, controlling space heaters via an elk thermostat and a UPB switch etc.
What's crazy is that these variables are available and can be controlled via applications like CQC, but not via elk rules. Even ELKRMS will modify the Mode parameter without a physical thermostat attached. I could solve this by writing all the Rules in CQC, but my philosophy is to use PC based applications like CQC to set variables in the Elk, but use the elk to process the actual tasks. I do this because I want a system that runs when the PC is not online for some reason.