Installing awnings with a "problematic" (?) mounting situation

The left would have been 5x4.5m and the right 4.5x3m

Shadone from shadesign de, about 8,000 €, completely done by the company

Looks good. I could also well imagine it as an alternative here with us. Are the motors in the mast? I would have expected somewhat less in terms of price, but yes, everything has its price.

the motor is in the shaft of the sail, in the masts are springs to tension the system and secure it against storms, on the wall is the small solar panel, but it also works with 220V

the motor is in the shaft of the sail,
there are springs in the masts to tension the system and make it storm-proof,
the small solar panel is on the wall, but it also works with 220V

Is the small solar panel sufficient to operate the motors? Does it also work on cloudy days?
In my case, power supply through the masts would be easier, but that doesn't seem to be possible.

The solar panel charges a battery that is attached to the shaft, so far it is running very well, the sail was one of the first in Berlin with a motor, previously always with cable drive. At the manufacturer, you should find installation companies near you.

A company (that installs Klaiber awnings) suggested simply attaching the awning to the brackets/mounts of the fall protection of the floor-to-ceiling windows. What do you think about that?

Nothing, absolutely nothing. Our awning has been anchored with a total of twelve rods, each approximately 30 cm deep, into the concrete ceiling using injection mortar. Care was taken to hit roughly the middle of the ceiling, and certainly not because one could have simply used a few hundred screws plus dowels. Sure, the awning has an extension of four meters, but the mounting of the grid is definitely several orders of magnitude too weak for such loads, even if only three and a half meters of extension are used.