We're looking into documenting this better but I was also not able to
make it work "out of the box". There is a ticket very closely related
to this: https://phabricator.wikimedia.org/T205922
Another place to find other people who might have similar problems is
the fairly new Wikibase Users' Group Mailing list which you can find
You might find also it useful to take a look at:
From the way you describe it your second problem is
related to the first one.