Looking forward to the riser and stage updates.
Good to hear from you. I was wondering how things are going.
I would think 7" would be fine. I don't have my screen up yet, but I was measuring various distances from light to screen and decided 8'-12" was a good distance.
I'm sure others will chime in who have their lights and screens up.
That is similar to my lighting layout, except I only have two lights in the back and four across the front. My room is about 19 x 23. I used the small 4" cans with 50 watt halogen bulbs. It is bright enough with all lights on to come in, pick your seat, clean the room, etc. Not as bright as a normal room though.