Hi there!
I wanted to share that I created a python backup script that can be found here:
Install the python requirements, supply email and password, and it will backup everything for you, with a file per tag, just like BazQux interface. It pulls all starred and tagged items, and converts them to markdown.
I hope it is useful for any other BazQux lover. It is ment as a readable disaster backup in case the service goes down, which I hope will never happen.