Looking at the interior I decide to not sand the interior to the bottom. this is one of those places where people simply disagree. Some would sand the interior to the bottom "just because" while others like myself generally leave it alone. A friend of mine used to say that hollowing a vase was too much work and just cleared as much of the interior as he could with a Forstner bit. He did nice work.
Any cuts to remove the bark need to work with the preceeding flow of the piece. This can be difficult as being so close to the holding power of the screws in the faceplate seems to encourage a hearty slice.