Smart replacement for old central thermostat for Wolf heating needed

Hi everybody!

We bought a house from 1963 (Germany) and I want to apply my Smart Home / Home Assistant skills I learned in the last two years.

What my current thoughts are about is replacing the current central thermostat for the heating, which is situated in the hallway and which is an anlog box from obviously the 60s (just a small wheel and a fancy analog representation comparable to a normal thermometer).

So, two questions:

  1. Which would be the best approach to replace that box? The heating is a Wolf CSK
  2. Where do you guys place the central thermostat for the heating or do you control it as a sum (e.g. max of all room thermostats)?

Have a nice day and thanks for hints!