We have had some problems when they are crowded. We keep ours in 1.2 or 1.3 groups. Once the babies are weaned, it's best to remove them from the breeding group.
They don't seem to take well to "strangers", so we use siblings to set up new breeding groups. Just seems to work better for us.
We've never had a spoilage problem with the 6F. We have food "hoppers" on our cages/racks that hold several days worth of food and we just top them off when needed. We never have to discard food.
I hope that helps you. Let me know if you have other questions. Good luck with yours.