I used a somewhat gauzey fabric that I picked up at the Pacific Fabric Outlet earlier this year. Not sure of the fiber content, have been too lazy to do a burn test. I put the fabric in the washer and dryer, and now the background is more grey than white.
Because this fabric is "striped," I cut out all the pieces in a single layer to ensure that the light and dark areas would be symmetrical.
back of garment
None, I made everything as drafted.
The sleeve cuffs have a really great design that you don't even notice until you trace the pattern (or someone tells you, like me...). To form the cuff, you fold under a deep hem, 2", and topstitch. Each cuff then gets 4 buttonholes and 2 buttons. Each button is fastened into 2 buttonholes; this helps to create a pleat. See the line drawing above? The cuff looks the same from the front and the back.
None, except that I typically avoid this style of collar (would you call this a mandarin collar?) because I just don't care for this look on me. I forgot about that when I chose this pattern!