Best comprehensive SmartHome program

What do you mean by that? Motion detectors with batteries? Connected to power would definitely be more comfortable

Yes. If you have found a detector with fixed power supply (without bus!) that works with EnOcean, WLAN or other radio, let me know. I haven't come across one yet. At most, just normal 230 V detectors with or on a switching contact.

You are right, I have not found any motion detectors with power connection for wireless smart homes.

The electrician explained Free@Home to me again; he would only do Free@Home in a decentralized way and only a mix of bus and wireless.

In the rooms, he would lay and loop the bus cable to the individual light switches and roller shutter switches.

In the stairwell, however, he would always use wireless to ensure wireless mesh coverage.
Window sensors are wireless anyway with F@H.

Since Free@Home in the decentralized variant and a mix of bus/wireless is not really optimal, I will then follow your advice and have everything wired conventionally and retrofit a wireless smart home later.

Doesn't Steinel have a 230V Z Z-Wave sensor?

IS 140-2 Z-Z-Wave