Please forgive if these issues have already been discussed, having trouble searching.

When making a Bible Study guide, is there a way to add more than one collection? I add the Collections section and have several collections I want to include but it will only let me add one. So I decided to make a collection with all the collections I want to include, which leads to my second question...
When editing a collection the Add section reads, "Drop resources or collections to add here" - but how do you add a collection? I can't figure out a way to list collections so that I can drag one over and drop it into a new collection. Am I overlooking it somewhere? Also, will the new collection dynamically update? That is, say I have the collection "John Piper Writings" and I add that collection to a new collection "Study Resources" and later I add a new book to the "John Piper Writings" collection, will the new book automatically add to the "Study Resources" collection?
Third question, back to Bible study guides. I have created a collection of commentaries I want to use when I am studying Ephesians. So in the Bible study guide I am trying to specify the "Ephesians Commentary" collection but it isn't letting me choose *any* collection. It says "Collection:" but has no drop-down list or any other such thing to let me choose which collection I want to use.
That will do for now!