A few breeding Qs

[jjnnbns]

I plan on breeding rats for a few months over the summer to build up a small collection of feeders, then feeding off the breeders as well as offspring to my snakes.
I've just got a few questions...

1. Are medium rats old enough to breed? (I'm planning on 1.2 or 1.3)

2. How long do they need to be with their mother (for milk) before they can be put in a new container to be bred to proper size?

3. How long does it take for a rat to grow to a medium size rat?

4. Do I need small airholes in the sides of the enclosure or just the hardware cloth on the lid? Will they be able to gnaw through with the small holes?

5. What is best to use for nests/bedding? Anything cheaper than carefresh? << I thought about throwing some cardboard and 'margerine-type' containers >>

Thanks for any help,
Brent

PS If we decided to do mice too, what would be the NECESSARY changes, ie how long before they can be separated from their mothers?