Hello! It seems you've gotten a lot of really good info so far. Looks like you've done a great job at doing research, and trying to figure out what you need to feed your babies, nice work! You obviously care a lot. If I were you, I could try to simplify my feeding schedule a bit.
Chickens are really good at knowing how much of what they need, so offering Oyster shell on the side rather than daily might work better for you. You can purchase corner feeders, hanging feeders, or simply use a bucket to hold it. I use an old dog bowl and a corner feeder. I love both! Just make sure its under cover so it can't get wet.
You can also feed your chicken feed free choice. You can feed it morning/night if you want, or if you are worried about rodents.
When you go to the feed store next, pic up an All Flock feed or Starter feed in a 50lb bag. I would get multiple bags so it lasts a while. Either feed is fine, neither contain calcium which is good. You don't want to feed layer since it can contain unnecessary calcium for your rooster, or for hens who aren't laying at the time. I feed a starter because of the higher protein. Especially in winter. Added protein helps them keep them warm.
I like to use an Organic Non-GMO feed, but thats just my opinion.

If I were you, my list would look something like this-
All flock/Starter chicken feed (depending on whats available)
Oyster shell bowl/grit bowl
Oyster shell
Grit
Also, I couldn't tell in your post if you were feeding Scratch mixed into the feed, or as a treat. I'll just put it in anyway. You don't want to mix scratch into the feed since it can cause a protein deficiency. The birds will likely pick the scratch out and eat that rather than the feed. You can still feed scratch, your hens will love it as a treat, mine love it! Just make sure its no more than 10% of the diet. Thats about 1 Tablespoon per bird per day.
I hope my post was helpful! Again, doing so much research for your flock, and even better job at posting this thread to make sure you were doing everything right. There always so much to learn.
