Rough estimate of renovation effort / costs

doesn't the one above have any (at least I haven't seen any. So the question for me is, what solutions are there.

I had a townhouse with only such gable windows on the upper floor.
You actually don’t need any privacy screen “up there” at least. Roller shutters are complex and expensive. You can put curtains there for a DIY method or just leave it as it is (that’s the charm of this dormer(s)).
Are there more photos? How expensive is the mid-terrace house supposed to be?

Then the attic is open at the top, here we are considering whether to either divide it or close off the room with walls.

??? What do you mean? Closing off the nice part?

yes that's true, the windows are great and have their charm, but if in summer the children are supposed to sleep already at 9 pm, although it is still light outside, then something to darken the room would be quite good. But curtains are certainly a good tip, otherwise there is also the possibility of using pleated blinds, I read that today. The terraced house in the middle is supposed to cost just under 600k. That is actually a relatively usual price for here, newer ones sometimes cost less, but they are mostly smaller, about 120 sqm. And this one has enough space and rooms. The thing about "closing off" the attic referred to the fact that I

How is it actually, just hypothetically: Since I am interested in 2 of the 3 properties, I would like to make an offer for both properties. If I end up getting the contract for both or first the confirmation for one and later for the other: how long can one still withdraw? 14 days should generally be possible, right? At least that is the case with distance selling ;). But probably I am legally in the wrong corner here. For one house it will probably be decided quite quickly. For the other, which I actually find quite attractive due to the larger plot of land, probably only 1-2 weeks later. From when do you commit yourself with a "confirmation" or from when do costs (compensation for the agent, etc.) potentially arise? I mean, given the tense market situation, you can hardly apply for only one, especially if you can also well imagine another property.

What is a bit of a pity is that there is neither a garage nor a carport included, but only 2 outdoor parking spaces. Next door there is apparently an underground garage where you can possibly rent a space. We would probably do that then.

Should I get the contract award for both in the end or first the confirmation for one and later for the other: how long can one still withdraw? 14 days should usually be possible, right?

When buying a house, only the notarial deed counts. Nothing else – so you neither can nor need to have a right of withdrawal. Withdrawal from what, anyway?! Of course, what can happen is that a notarial deed is prepared at your request. Those would be costs you’d have to bear if it is not signed. The real estate agent is just out of luck then. There is no compensation for effort. He gets his commission upon a successful sale. That is compensation for effort enough.

Should I end up getting the contract for both

My crystal ball is having its esoteric day today and says: if you doubt your two chances, you wouldn’t get either. Put everything on one card, even if combined energy is not yet a guarantee of success. If you don’t know which one, then take a die or toss a coin. What good is a bare braid – decide on heads or tails. Whether the crystal ball has read too much Confucius or the bowl with the fortune cookies is standing too close, not even Rumpelstiltskin knows that yet. You have to live with this residual risk – Tel Aviv, as the French say ;-)