Bug 1
This bug is related to tag afb-4634. The two bugs reported with embedding documents were fixed when creating new documents, but still exist when opening existing documents before the bug fix.
Bug 2
After embedding a document into another document, selecting a Page Box option, saving, closing and reopening it, the embedded object starts out small. When selected for the first time, the embedded objects pops into the actual size. The application is usable, but the experience is jarring and the application feels broken.
This can be tested by first creating a document with a square smaller than the document size. Create another document to embed the first one. Select "Minimum Content" as the Page Box option, then save, close and reopen the document. The embedded document will appear small, but when you select it either in the layers panel or in the main art board, it will pop into its actual size.