1. api doesn't exist (yet)
2. yes, it's possible to register outside and 'cause ubbt to create a threads user' -- custom modification, that has been done before
3. no, it's not as simple as running one SQL query, but doable
4. no documentation for a developer. it's open it up and peeky time only
5. not self explanatory, but the DB is easy to learn after poking around.
