I don't think the Visio chair images are to scale, but honestly we really only need six seats for 95% of the things we would host. During the occasional sporting event (PPV, Superbowl, etc.) we may have up to nine people or so - at least that's what we've been averaging the last few UFC and boxing PPVs. I suspect that number could grow as the theater makes coming over more of a draw.
Once the walls are built, I think the final room width with be close to 12.5'. Based on what I've read that is a bit tight to fit 4 seats. Besides, we can always order another seat if needed.
The equipment closet just seems like the ideal spot if I want to keep the gear out of the theater and still have easy access to it. I'm picturing the rack facing out into the entrance hallway across from the half-bath. I could either put the access door going into the theater and hide it, or just not but a wall between the equipment and the fridge and just slide out the fridge to get to the back of the rack.
What the drawing doesn't show is that the frig and equipment closet makes use of other dead space below the stairs. You can see it in the photos (I think) on the previous page. If not, I'll take a photo and post. Also, the water heater and HVAC aren't to scale, but the bath and hall dimensions maximize space without requiring anything to be moved.
As for projector mount, ideally I would like to have it behind the back wall, but because it may be a couple of years before I actually buy a projector, no final decision has been made. A lot will depend on what projectors are on the market then, throw distance, CIH compatibility, etc. Either way, I plan on allowing for some flexibility.