Your tank looks great! I would be wary of the castle ornament as it has sharp points that could tear a bettas fins or scratch his sides. Also make sure that the driftwood does not have any sharp points/edges where your betta could snare his fins. If it does just get some sand paper and sand the area nice and smooth and rince before placing it back in your tank.
You will also need to watch that the filter inlet does not suck in your betta or his fins. To eliminate this you could place a small peice of stocking/pantyhose material over the inlet and use a rubber band or something along those lines to hold it in place.
Your tank looks so nice, I am sure that your betta will be very happy in there.