Q2 Interior plaster - possibilities?

filling, sanding, priming, painting.

what is the fleece supposed to do with settlements? hold the wall together?

It is not supposed to tear but rather respond flexibly to the settlement due to the textile content (as opposed to paper wallpapers).

We only primed and painted our Q2 plaster (08/2017). A painter did the priming. He also repaired rough flaws in the plaster.

So far, we only have the usual cracks between the ceiling (on the upper floor; wooden beam ceiling with drywall) and the walls.

The walls have almost no cracks. Fleece was applied to the ceilings on the ground floor and upper floor. I would always do it that way again.

I would like to have a fleece applied because of cracks

There are no cracks in the middle of the wall anyway (if there are, then something went wrong). Possible exception at the roller shutter box above the windows.

The corners always crack (with or without fleece), meaning renewing acrylic joints during the first period is unavoidable anyway.

There are no cracks in the middle of the wall anyway (if there are, something went wrong). Possible exception at the roller shutter box above the windows.

Just out of curiosity. What about the outer overhangs of the windowsill towards the floor? In all our rooms, there is a vertical crack going down on the left and right there. Is that still a rather normal spot?

No, nothing happened on our side. Only, as mentioned, above the windows on the left and right. It was fixed before handover (with additional fabric) but a crack is there again now

Painter's fleece is an elastic term. They also come in various qualities and weights.