Which internet Wi-Fi mesh system?

What do you think of the ceiling and wall access points from TP-Link?

My question would be, what is the range?

One access point should cover about 30-40 sqm per floor, right?

On the 1st floor, you could screw one to the ceiling in the hallway, then the adjoining rooms should already be covered, right?

In the attic, one access point should also be enough for the studio, about 30 sqm, since it's only one large room.

In the basement, one access point in the technical room should also be enough, since fast internet is not that important there.

On the ground floor (open living room, dining room, and kitchen), the question would be, if we put one access point in the living room, will we still have enough Wi-Fi in the garden to surf, or do we definitely need another access point on the terrace?

In the garden, I would plan an extra access point. Otherwise, you won't have good network coverage in the garden. If you have a reinforced concrete ceiling, an access point on the upper floor will not provide WLAN coverage on the ground floor.

The range is similar for all APs because our transmission power is limited. In the garden, definitely use an additional access point. In the basement with concrete walls, you only have wifi in that room. Better lay more cables. You start with few APs and if it’s not enough, you can still upgrade. All walls, glass, etc. shield the signal. 2.4 GHz goes further but is slower. 5 GHz is quickly "absorbed".

We are building with the developer

what exactly do we need to prepare for the Access Point?

I understood it so that we need a POE cable for every Access Point, so then centrally from the technical room to every Access Point and in the technical room connect to a POE switch?

Did I understand that correctly?

A Latkaben or Cat6 or cat7. In the technical room, you then have a switch with POE or with only a few POE devices, you could also work with injectors

ok the cable must then go directly from the POE switch to the end device or make the entire Ethernet socket POE capable and from there to the end device?

I have another question about a normal LAN switch. Does a LAN switch reduce the internet performance or does it have no impact?

Of course, if several devices need the internet at the same time, the internet is divided, but the performance is not significantly reduced just by a LAN switch, right?