Thermostat schedule rules

This may not be in the right section, however I'm looking for guidance on the best way forward.
I'm UK, so I don't need cooling the place

I'm effectively looking to put together my own dumb heating controls and zones. I'm basing the hardware on a simple zigbee switch that turns on the heating (combi boiler) and an external temp sensor

First stage: Would like to turn the heating on and off per schedule and then turn off or on if away/home mode changes. This uses a single temp sensor for feedback.

Second stage: Use multiple temperature sensors around the house to augment first stage, or if in particular one room has not reached the required temperature.

Stage three: Use all above and change mutiple z wave TRV setpoints to get the rooms to higher or lower temperatures depending on the status of the house temp or the room temp.

Stage Four: Advanced scheduling: Turn on and off TRV's in some rooms at different schedules throughout the day.

  1. I would like to concentrate on stage 1, which would effectively replace my house thermostat. Would the thermostatic scheduler be the most effective way for this. I have had a play around this, but I can't connect the dots with how I get a temp reading and turn the zigbee switch on/off with the temp set point or schedules?

  2. I assume some averaging temp app like Cobra has made in the past would take care of looking at multiple temp sensors and placing the average into a virtual temp sensor.

If anyone has something like all of this or some of this in place, would love to see the RM's, general guidance also is always appreciated.