It sounds lovely and I had a betta that loved that broken urn decoration. They play in and out of it all the time. They love going into nooks and crannies, that is why the "Rule of Thumb" is so important. Bettas will try to get into any hole they see and some have gotten themselves into trouble. So if your thumb goes into and out of the holes in the decorations, it is safe for the betta. Otherwise some changes are necessary or a different decoration. I also run a nylon stocking over all the decorations I get as if they snag the stocking they will tear the bettas fins and cause a fin problem later. An emery board or a piece of fine sandpaper will generally take care of most snags and the decoration will be fine.
The tank and theme sound wonderful I am sure he will love it there. Please remember to check the ammonia levels in the bowl daily until you move him to the tank and then if the tank is not cycled it will need frequent water changes to keep the ammonia down.