assuming you are using clones 1 plant per sq ft is probably sufficient with a 2 week veg and many sog are often done with as many as 4 just rooted clones per sq ft with no veg time.
as per your setup of placing it near the walls to maximize light reflection it is a valid point but it can also be a hassle growing in soil in pots that you have to water and feed at regular intervals and would be better suited for a hydro system seeing how you probably dont have room for good access to all sides as dont think 6 inches would be of much benefit would probably try to have access to atleast 2 sides.