Hi!
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 at: https://lists.wikimedia.org/mailman/listinfo/wikibaseug
You might find also it useful to take a look at: https://www.mediawiki.org/wiki/Manual:Sites_table#Adding_a_new_site.
From the way you describe it your second problem is most likely
related to the first one.
Best, Tom