I realized that I am stuck on the starttimer thing… Ideally, each room in my house would have its own starttimer, but it seems that the starttimer is set to each PLEG instance (of which I have only one). Am I mistaken?
A PLEG device can have multiple SelfTrigger or SelfReTrigger timers defined under Schedules. You start or restart the timers using the StartTimer action - specifying the name of the timer to be started. Consequently you can have as many timers as you need in one PLEG device (if there is a limit it is probably very large!).