Consider the following

I only have to give way to traffic from the right on the intersecting road: Incorrect, the mandatory sign does not regulate priority.
I am not free to choose which way I turn in the crossing: Correct, you have to turn right according to the mandatory sign.
I do not have to use my indicator when turning in the crossing: Incorrect, you must always indicate when changing lanes or turning into a new road.
I can turn into the first intersection as the whiteboard on the right shows there will be two lanes in 400 meters: Incorrect: that board is assigned for the lane at the top. where it indicates that lane will get a center barrier. The first intersection will have a board closer to the entrance notifying you how the road would've linked up. It doesn't so it means that road goes somewhere else

Direction to be followed (D1)

"The signs indicate that the vehicle may only be driven in the direction of the arrow or, in the case of two arrows, in either arrow's direction. The symbol is adapted to the conditions of the location."

Direction to be followed (D1)