Well, I finally finished block 5 last night and I actually remembered to do the backstitch steps and window panes. Haven't decided which block to do next and in fact, I may put it down for a nap while I do some smalls for Christmas.
The white areas don't show up well in the photos, but they show up well enough in person that I have not yet decided if I'll outline them. If I do, I'll use a very pale gray.