Does the room have to be that dark to see the picture from a abode theatre projector?

How dark would you say? How come a lot of people dont buy HD projectors instead of tvs since they cost little and have bigger picture?

Does the room have to be that dark to seat the picture from a home theater projector?

It definately has to be darker than if you were watching a tv. Within my apartment I would have to buy new heavy duty curtains to chuck over my windows.

Does a home theater projector need to be direct centered with the surface?

Not exactly, as a feature known as keystone correction can fix the trapezoid effect that may occur. My projector is just ever completely centre to the screen, but raising the projector's legs can also relief too, just make sure that the projector is witin almost 5 cm at te maximum of where the centre is ballpark to be.