Blackstrap molasses has higher vitamin and mineral content than regular molasses. Significant differences between the two. Whole wheat flour preferred because it has all the healthy parts of the flour. Refined all purpose flower removes the bran, which is where most of the nutrition in flower actually is. If you buy whole grain wheat and grind your own flower, then you have really healthy whole wheat flour for sure. The taste is amazing, and very different from most anything you might buy in the store.
But as others have stated, flocks don't actually need flock blocks. It's like putting a big pile of scratch in the run, and can mess with their nutrition a bit. However, if you're doing it as a fun enrichment boredom busting activity, have at it - occasional flock blocks shouldn't be too big of an issue, depending on how many birds you have, and how much of it they eat at once.
NOTE: Those recipes contain raw egg. So make sure you only feed these in cold weather, and that they are consumed before the egg can turn rancid. Store them in the fridge or freezer only for as long as you would raw egg.
Commercial flock blocks put as much nutrition as they can into them, but they're still very similar to scratch as a food source. For straight up nutrition, a good 20% protein all flock or layer feed is the most balanced method, and is all that a flock needs, even in the coldest weather. Feeding scratch or a flock block won't make them warmer. I don't know where that myth originated, but it isn't true.