I don't like the Kaytee products.

But for the scattered food issue, you will have to only give them enough to finish in a day, after a few times you'll find out how much they can finish in a day. Rats will stash their food regardless of what you do, it's just what they do.

If you want less waste, you can use lab blocks in a hopper made of 1/2 inch hardware cloth. No waste and the rats have food 24/7.