Epson S1 Zoom Question - Please help

I have a Epson S1 LCD projector.

My question is

What is the zoom range/ratio from minimum to large?

I am in the process of mounting the projector and there is no on screen indicator on the digital zoom to show when the picture is at 1:1 (no zoom)

The manual says the project can zoom to 1:1.2 does this mean when the zoom is set to its minimum that the picture is at actual size (no zoom 1:1)?

I read on the internet that by using the zoom the picture can degrade slightly so therefore I wish to mount the projector where I can get the size picture I want all the while know that I am not using any digital zoom.

Please help

Thanks in Advance

PS: another question which is a long shot is ... Does anyone know the ceiling mounting screw (screw holes on undersideof projector) size and whether it is metric or imperial.

I brought the project from Frys in LA