Sure you could use a spare room for your sewing room. One question though... do you cook? :lol:
Yes, it has a 4th rail that is hidden by the cross supports. Your frame looks brand new! I hope mine looks as nice many years from now.
I'll have a quilt on it ASAP. I need batting and backing which I can probably get during lunch today. I ordered 108" backing fabric for 3 quilts but not for the one I want to get done first for my brother. I need thread, perle cotton, embroidery floss... and whatever else looks like I need to get it at the store.