Fetching Facebook posts
Here's the solution I got on the main stackoverflow site (https://stackoverflow.com/questions/31306242/facebook-graph-api-unsupported-get-request): 

If page restrictions apply, the page's feed can only be retrieved with an user access token as far as I know (because FB needs to evaluate the visibility criteria, and setting your app to the same restrictions doesn't help here):

See

https://developers.facebook.com/docs/graph-api/reference/v2.4/page/feed#readperms


The alternative is to use page access tokens, but you need admin access to the site page to generate those. This means you will receive all posts, regardless of restrictions.