Size of courtyard entrance and planting strip as a visual barrier?

There are other options and different preferences. Depending on the hedge, I would decide where the fence goes. Thuja is toxic to dogs. Not every dog goes near the plants. Is 1 m height enough for the dog?

Since the street is a dead end and large parts of the driveway are private (it's a single-family house, right?), I would place a larger opaque gate and a wall-hedge combination at the edge of the property facing the street, a fence/hedge at the property boundary, and the driveway would then be part of the garden. I find the "bottleneck" unproblematic, better to have a bit more garden than paving. With this solution, the dog would also stay on the property. The garden area would be less cramped with a dividing hedge within the space. Beech hedges are dense enough even in winter, easy to maintain, and become dense fairly quickly.

I would probably have extended the planting strip straight to the front. A 3.5m driveway width is definitely enough. The other bend can stay.

The consideration with the "lower bend" was that a car could still be parked there if necessary.

No, but if a bike, tricycle is parked or friends park, it simply gets tight.
I would never have placed the garage that far back.

I see bike etc. more directly in front of the garage at the entrance. There is enough space here. Garage that far back

Depending on the hedge, I would decide where the fence runs.
Thuja is toxic to dogs. Not every dog goes to the plants

Is 1 m height enough for the dog?

We had also thought of Thuja so far and placed it in front of the fence so that the dog is not constantly with the Thujas in the garden. 1 m height, possibly 1.20, should be enough. We have a Beagle. More the digger than the jumper ;-)

Since the street makes a bend and large parts of the driveway are private (it is a single-family house, right?), I would put a larger opaque gate at the front and a wall-hedge combination at the property boundary to the street, a fence/hedge at the property boundary, the driveway would then be part of the garden.

Yes, it is private (single-family house). The idea is good but unfortunately not feasible. The small triangle below (parcel no. 5409/4) belongs to us together with the neighbor, as his driveway goes down here next to our path to the basement door (next to the red area). Furthermore, I like to keep the driveway separated from the garden because otherwise you always have to watch the dog when opening the gate, etc.

Well then, Thuja and fence between garden and yard. Although I like Hampshire's suggestion best. Leave the triangle clear, then the gate doesn't have to be opened for every short jump.