Lighting planning in kitchen, living room, and dining room + smart home technology

For such a special design, I would go to a lighting planner. They can also simulate the whole thing on the computer.

And is DALI simply a MUST here, or can I still do it with a KNX dimmer?

If you stick to CV light sources, the question of DALI or KNX dimmer is a matter of calculation. From a certain number of dimmed circuits, DALI is simply cheaper, with RGBWW and the like even much earlier. If we are talking about normal light sources and not native DALI lamps, the dimming behavior of DALI does not differ from a good KNX dimmer (Theben, the new MDT LED controllers, etc.). If you want to work a lot with CC, you can hardly avoid decentralized electronic ballasts, and that is then the strength of DALI.

Also to consider is the number of desired groups from the electronic ballasts when working decentrally, which rather affects CC light sources (which I see in practice mostly in lighting planners).

In your plan, you have multiple power supplies; this would work with CC strips with multiple DALI electronic ballasts, which can be combined into one light circuit with two clicks. With central dimming, you have really nice power supply packages, repeaters, etc., all of which get warm and require a lot of space in the distribution.

What do you think about the planning? Does it fit the floor plan? Are there possibly too many spots? Where could floor and side lamps be placed?

I think the number of spots is right. I might miss two spots in the master bathroom along the walking paths in the "bath area." I notice that apparently no LED strips are planned. I find a combination of spots and strips quite nice, as strips, for example, can provide glare-free ambient lighting for general brightness and can set subtle room accents. Ps: nice room layout!

And is DALI simply a MUST here or can I still do it with a KNX dimmer?

I can provide an older example: since 2016, 24v LED strips (warm white, no RGB) combined with central Meanwell HLG power supplies and eldoled lineardrive drivers have been illuminating an attic floor. The ceiling is drywall. Of course, there are also individual regular light outlets in addition.

Here are some more photos of the living/dining area, bathroom, stairs...

Thank you very much, nice idea. Do you still remember which profiles / aluminum rails you used there? Are the LED strips rotated 90° or do they shine straight down?