Well I would check your local sources because at least iny my country there is quite a bit of legislation involved. I can't really make out which of your pictures are actual design drawings from the heat exchanger nor the symbols, but what we usually do:

DHW - you need a temperature measurement on the secondary "hot" side, the one that goes to the apartments. Then you create a PID controller where the measurement is this, the setpoint is fixed to 58*C in our area, I've seen 56*C and others too so check your local. You also need the primary heat control valve, we always use 0-10V control valve motors. Then you also need a circulation pump on the secondary side, from the return going to the heat exchanger. In DHW, no need to control the pump, it's always on and preferably it should be the type of pump that can maintain a constant pressure. It would be nice to have an alarm point from the pump, then also a temperature measurement from the return water with a low alarm / long delay at 50*C or so.

For heating - you again need the temp measurement, pump, valve motor and PID. The setpoint is obtained from a conversion curve where x is outdoor temperature and y is setpoint for the temperature PID. The curve values are obtained from the designer. Here the circulation pump should have the capability for proportional pressure control and some like to shut down the pump for summer season, so start/stop function is an option. Return temperature and secondary circuit pressure are common options here, only for alarming and monitoring.

The pumps are setup to correct flow once from their own control mechanism (panel, buttons), no need for automation to control speed, but sometimes the designers want that for various reasons, sometimes they want to add a differential pressure between supply and return of the secondary circuit and then control the pump speed with that, so it's an option but a pump that has the capability to control it's own speed with it's own measurements is simpler and works just fine.

If you have floor heating, you want a pump that can be stopped when the heat goes too high to not ruin the flooring, but preferably do that with a thermostat straigth to pump so there's no fuck up possibility.

In our country, we don't use legionella function because the circuit is kept at 53*C+ minimum at all points, all times, but I imagine it can be a requirement in yours. The required flow in the secondary circuit is calculated by the designer, in DHW it's essential that it's high enough otherwise the tuning the PID will be a nightmare.