BB: One thing jumps out at me right away, and that's the top rafter pair. There's nothing tieing the rafter feet together. Since the roof pitch is less than 12/12, the outward rafter thrust will be greater than the roof load. In your case, the center posts will experience a large bending force right where the shed rafters come in. Also, the joint where those posts join to the upper tie beam is in a great deal of tension. You'll have to do the math to see if your post is big enough to handle the bending, and the joint is tough enough to handle the tension. CB.
