On citations, there seem to be an extraordinary number of trees with no sources at all for anything! On syncing Ancestry is supposed to add a general "Ancestry family trees" source for all new or supporting facts added to one's tree from other trees. But it doesn't, or at least only does so randomly. I forget how many times I've had to go through cleaning up, just to link that source to facts, so it sounds like you may get irritated, too!
There are also batches of sources which are only cited in the Ancestry text, with no images. These often don't get properly cited when attached to a person, so I've taken to going back to the source on Ancestry (after syncing), copying the text and pasting it into the source details in FTM. Depends upon how perfectionist you feel you need to be!