I second Clear. For us to even begin to tell you how many to get, how and when to breed them, how many to hold back etc etc etc, you should let us know how many snakes you have to feed weekly.

We have a sticky here Should I breed? How many to breed? that should answer most, if not all of your questions for breeding, costs, and number of animals to keep in regards to Norway Rats.

Also, we have another sticky here for you, Feeder FAQ's that will likely answer the rest of your questions concerning breeding.

It should give you a base of knowledge, rather than asking us to type a booklet for you, and then we can answer some more specific questions. It's quite overwhelming trying to read your entire post, then to go back and start answering all of the questions, which seems to be just about everything.

But like I said, we really can help you know what to expect if you tell us how many you need to feed weekly.