I don't have an answer to the first question, but as to the second one, if you keep the fry in with adult fish, they will become tasty snacks. A few may survive, but not all of them.
I've made a temporary breeders box out of a rectangular gladware storage container (plastic) and a nylon. Cut the bottom out of the gladware container, insert it in the nylon, and cut a small slice in the nylon covering the top of the gladware. The hole in the top of the nylon will expand nicely so you can add food, and the open bottom of the gladware will allow tank water to flow into it, while the nylon keeps the fish from swimming out. I secured the gladware container to the side of the tank with a few spring clips. Worked to keep the fry isolated until I could get something more permanent.
