Thanks to both of you for your response and advice. I am tempted to use lens shift to avoid installation headaches but read somewhere that it's best avoided when using a lens. If I choose to do so I could have everything sitting on the shelf as opposed to hanging which obviously has more work involved. But sitting on the shelf would take the projector just above screen height and I would definitely have to use the lens shift.
In regards to the screen I'm using, it's a Seymour center stage XD Acoustic transparent screen so I don't imagine it's too reflective but I'm more than happy with it.