One other point that I have wondered about has to do with the strength of the miter lock joints at the corners. The installation of the floor will help to some degree in holding the four wall together, but the corners seems to me to be very important, but I am going to go ahead and use the miter lock joints, they are already cut and they look very good.
The corners are going to be long grain to long grain, and the glue will be plenty. You might simply want to use a rabbet-Dado joint to join the corner. Easy to make, lots of glue surface, more tolerant of a little misalignment than a lock miter. Just remember that piece y will be shorter than x so it looks even when assembled
Last edited by TwoSkies57; 06-27-2014 at 12:06 PM.