Electrical installation - Retrofit switches/buttons wirelessly

also the Eltako FD62NP-230V as well. You have to set the operating mode to "phase cut".
Provided you use EnOcean pushbuttons

What does "also" mean? I previously talked about an FL62NP-230V.

1)
If I use conventional switches, can I still dim? I actually want to keep the conventional switch as it is, but additionally be able to switch the spots on/off and dim them remotely via a signal (e.g. from a logic circuit ioBroker, FHEM, etc.).

2)
If I now connect spots with their own transformer everywhere in the 230V line, can I still dim the spots?

It cannot be said in general terms because it is not the buttons but the wiring that is decisive.

Can you briefly explain to me how the wiring must be?

If you want push buttons and conventional, I would do it like this:

Light switch -> Cable directly to the junction box.
Light outlet -> Cable directly to the junction box.

If you want push buttons and conventional, I would do it like this: Light switch -> cable directly to the switch box. Light outlet -> cable directly to the switch box.

The installation is already finished. I am basically just about to have it inspected. I would like to check the wiring myself, as it is still accessible and no meter has been installed yet.

Oh I overlooked that.

Can you briefly explain to me how the wiring has to be?

There is no clear answer to this question. But you need all 3 wires at the light switch and light outlet to be as flexible as possible. Simply put, you should also be able to install a socket at the location, then almost all options are open to you. Just as T_im Norden has already described. Star wiring, exactly.