I would love to have access too, once I had to access to it and I had to send to TW R&D to get the problem corrected
James, is there any particular reason since it's strongly recommended against changing anything directly on the Database, while by passing the ThingWorx application in between.
Any direct change there could lead to data loss/corruption.
If it's just about viewing the structure you can use Neo4j community edition tool. I believe you'll need one of the older release 2.x to be able to connect.