I would place it pretty centrally, but there are different opinions on that. What is more helpful: an extra empty conduit and socket at the top in the corner for the motorized screen!
You can't really say that in general. It also depends heavily on the projector itself. There are some calculators on the internet where you can enter different models and each time you get a different value.
If you are unsure, have several sockets for spotlights installed in your ceiling and connect them with an empty conduit as well. Then you have enough options. There is also space for a power outlet in the spotlight socket.
We have consciously decided against spots in the living room and have only one fireplace.
However, exactly at the place of the fireplace would be a quite good position, since the projector would then not necessarily hang above the couch and people's heads.
After 12 years with a projector, I completely abandoned it in the new house, it was annoying to always have a quiet humming from the fan, expensive lamps, then my old projector no longer has HDMI, it always has to be quite dark, etc. Now I simply have a 75-inch TV on the wall, nowadays there are even 80 and 85 for 2000 euros, the projector also cost that much.
Alternatively, the Laser Projector from Xiaomi only needs 30cm wall distance
We consciously decided against spotlights in the living room and only have one connection point.
However, exactly at the spot of the connection point would be a pretty good position, since the projector wouldn't have to hang directly above the couch and people's heads.
I don't mean spotlights, but a spot box. You can't see it after the painting work is done. If you install 2-3 of those, then you have different positions available.
After 12 years with a projector, I completely gave up on it in the new house, it was annoying to always have a faint hum from the fan, expensive lamps, then my old projector no longer has HDMI, it always has to be quite dark, etc. I now simply have a 75-inch TV on the wall, meanwhile there are even 80 and 85 inch ones for 2000 euros, the projector also cost that much.
Alternatively the Xiaomi laser projector only needs 30cm wall distance
I understand. However, a decent projector for about 1000 € can achieve a diagonal of over 130" – you can forget about the 85-inch TV. We sit more than 5m away from the media wall – bigger is better there. My current 65" from about 2.5m is already too small for me.