Spackling Q2 / 2 coats of paint - sufficient?

Well, things are getting better again. Silicate paint is additionally mold-inhibiting, if I remember correctly. But in a modern new building, it's basically not necessarily needed. Do you have ventilation?

Yessir, we have installed a central ventilation system :-)

I was actually "pro" silicate paint, but the dispersion paint seems to be very good according to the datasheet as well. Especially since it is already vapor-permeable, I suspect that a silicate component has been mixed in...

The better ones, even from the DIY store's own brands, are actually always available nowadays. It has just become too well known that pure dispersion is a perfect breeding ground for mold...

When doing it yourself, by the way, I would always use at least dispersion silicate paint because it is easier to apply, if not pure dispersion paint (with a silicate content). It simply spreads much faster and easier. Since you don't have to do it yourself here, I would possibly still go for the pure silicate paint despite the extra cost. Just for the better feeling afterward. But I don't know how much you would miss that elsewhere.

Dispersionsfarbe: Brillux Malerweiß ELF 956 Silikatfarbe: Brillux Profisil 1906

Just FYI: Both contain titanium dioxide. The EU has classified it as suspected of causing cancer.

A pure silicate paint is usually not applied indoors; the paint offered here is also a dispersion silicate paint. My certainly not so objective opinion is generally also pro silicate. But I primarily work with such paints as well.

You first mention a €1 surcharge per m² and then €1400 for 200 m²? A €7 surcharge seems steep to me. There is not really more work involved in painting and the material price is not so extremely different.

And the risk of titanium dioxide in paints is not comparable to intake through tablets or dusts.

Approximately 200 m² area... yes exactly 1400 € net is the extra charge for that.

wall area??? I somehow thought 1€/m2 surcharge

I suspect he means 200m² of living space and 1€/m² of wall area. That would be about right, wouldn't it?