Smart home planning - is this basically suitable?

I could now continue asking what you wanted to depict - if not that :)

Well, the plan is still in its infancy and basically you are describing what is commonly understood as smart home and you don’t really need KNX for that. Only when you really want to go deeper into the subject does it become easier with KNX than with many other systems (keyword: interoperability) and often also more attractive to look at (keyword multifunctional sensor switches instead of boring switches).

If you only want the usual remote control capability, that can be achieved in other ways as well.

Dimmable sockets are a no-go. Regarding retrofitting, I don’t quite share the opinion/experience of undergasse43... there are simply different kinds of installations. It also depends on the user. Either he is tech-savvy and capable or he always lets the SI come. For the first, retrofitting is possible and for the second rather not.

Virtually mapping the existing, physical KNX system.

That is actually the main task. Because otherwise, why else?

How much does a car in the mid-price segment cost?

I have seen the question so many times now and thought I would give an answer: 40,000€.

Well, the plan is still in its infancy and basically, you are describing what is commonly understood as smart home, and for that, you don’t really need KNX. Only when you want to go deeper into the subject does KNX become easier than many others (keyword: interoperability) and often also more visually appealing (keyword: multifunctional touch sensors instead of dull switches).

If it’s only about the usual remote control capability, that can also be achieved in other ways.

No, it’s not about remote control for me. I wrote that I want to gradually integrate scenes and automations myself via the visualization/logic. It’s initially about the hardware, the basic setup, and then whether gradual expansion (especially software but also hardware) is feasible as I imagine.

Yes, with KNX you can't go wrong. You create an infrastructure that is independent of the usual and limited conventional electrical system. You can then also adapt and change it as you wish even after years.