Weighing different options in the single-family house

The police recommend RC2 on the ground floor and the upper floor everywhere the window can be easily reached, for example above the carport. I assume the police have a better overview of the sense and nonsense of such things, so I would follow this recommendation.

we are currently planning the construction of our single-family house and I would like to clarify as many details as possible and make decisions about the equipment before contract signing.

However, I still see that as quite far away.

By the way, I am deeply shocked at how little you seem to read in other threads (and in my info blog), because on many points both the community here overall and I myself here and elsewhere have actually already examined almost everything in detail.

Regarding the points individually:

(7) from my point of view the most important. The whole range of upgrades and changes will meet with little approval from your wallet, but the even higher doors (opt for the higher of the most common market sizes between 201 and 213) will be the order here.
(11) Caution risk of timing! (also with regard to threatened price-fixing periods).
(16) Warning burglary risk. This is generally increased on rear entrances, even more so on sides turned away or in the shadow of canopies. Side entrance doors are regularly underestimated here. I would possibly even reconsider the "necessity" of the pastor’s and mayor’s entrance and consider a proper single entrance door to the utility room (as a chatting door?).

(1 and 9) Aluminum and increased burglary resistance class on the ground floor and on windows on the upper floor that are accessible via the carport or other canopies; my "color choice" for aluminum roller shutters would be "natural" anyway.
(2) I would not link venetian blinds and roller shutters with OR.
(3) Approval, but see Steinemantra ;-)
(4) on controlled residential ventilation, I believe I wrote the most about it here in 2018. Summary: if consistently or predominantly, then central: and especially for allergy sufferers noticeably advantageous for about the first five years, after that the contamination issue comes up.
(5) nonsense twice over (back-of-the-envelope calculation and static issues), see "Lightweight walls in solid houses?" and "The upper floor has priority". Especially in the "one-and-a-half story" with its sloping upper ends of the walls, lightweight walls are the best choice in most places, in some places I recommend gypsum boards.
(6) we have more threads about that here than I could link to ;-)
(8) utter nonsense. Most noise on stairs is the noise that other components transmit. I would always also take risers, and preferably mounted stairs.
(10) I would generally take normal swing doors (if covered, preferably opening outwards). You only have a significant improvement in driving rain tightness if you do without the flat thresholds ("Barrier-free window doors thanks to flat thresholds").
(12) don’t forget when pre-installing to leave out the heating loops.
(13) home automation can never be planned too early, in execution it is a classic topic outside the competence horizon of the GU subs.
(14) it’s the other way around. I haven’t watched any program-synchronized TV for twelve years and I make landline VoIP HD calls via cable internet. For triple play it doesn’t matter whether the provider calls its network telephone or broadcast network; sometimes one and sometimes the other network operator switches to fiber optics earlier. In-house you have nothing to do with TAE or coax sockets anymore today, but everywhere RJ45 in a patched star network (there are also several threads about this here, including with the search term patch panel).
(15) washbasin and cleaning basin (preferably with indoor-outdoor water tap for the garden hose above it). I think the posts by could become your favorite reading.

The police recommend RC2 on the ground floor and the upper floor everywhere where the window can be easily reached, for example above the . I guess the police have a better overview of the sense and nonsense of such things, so I would follow this recommendation.

Maybe one more addition. The recommendation is RC2N - so not the secure glass.

About 80% of burglaries are opportunistic break-ins through open doors and windows (at least according to the police prevention portal) or the majority occur through very simple prying attempts - so always close windows and lock doors when you are not at home.

Final addition: RC2N should cost somewhere around 20-35€ per window (depends on the size). My window dealer, for example, does not sell RC1 windows anymore.

Re. 14: How does the internet come into your house? For example, I get 1GB via cable, DSL from other providers would be around 250mbit. What kind of connection do the neighbors have and are they satisfied with it? What performance do you need? I regularly hear that one or the other technology fails on one street or another, I would be glad to have options.

6. only makes sense if the controlled residential ventilation is separately blown in and extracted in the rooms. Otherwise, it must be overflowed.

(2) Roller shutters vs. venetian blinds on the ground floor
Decision: Roller shutters
Reason: Venetian blinds are vulnerable to wind (Northern Germany) and also somewhat more expensive; with some automation of the roller shutters, hopefully, you won’t be sitting in the dark in summer

That also depends a lot on the floor plan. We have windows from east to west in the open living area, so you can always leave at least one side bright. In the open living area, you don’t usually spend much time during midsummer days anyway, so that’s relatively uncritical. Bedrooms are also uncritical since you’re not in them during the day. Much more important are, for example, the study and children’s rooms. Ideally, these have windows facing two directions, and one of them faces north.

(12) Bathtub
Decision: No bathtub in the upstairs bathroom, but prepare connections for possible retrofitting and use for washing machine
Reason: We are not fans of bathtubs and would like to save the costs; however, we would still prepare the installation in case we ever change our minds or for a higher resale value

You build for yourself. If you build without a bathtub, then do it properly and don’t reserve space for it in the floor plan.

(15) Second sink in the utility room
Decision: Still open, cost/benefit consideration
Reason: Would be a nice feature for the kids’ dirty shoes or cleaning fish (I’m an angler)

One sink is enough

(16) Second front door from the carport into the utility room

It costs you a lot of storage space in the utility room and if you do it properly (keyword burglary protection and thermal insulation), also a lot of money. Especially if the front door is nearby anyway, such a door is more of a status symbol than something practical.