Might be interesting to put an orders placed tab on the top bar for buyers. I just had a buyer who had no idea whatsoever where to look to get an overview of the order just placed. Even I had to look for a while. Might even be interesting to have a Dashboard tab which joins both order placed and received as well as tasks (both for buyer and seller, like messages to respond to, feedback to post, ...). The My Store tab could then be related to all the other store things like quotes, inventory, settings, etc.