Breeding can happen without a nest. Some males just are not good nest builders and will either make a very sloppy one while actually breeding or use their salvia to get the eggs to attach to the glass on the surface of the water, so don't fret if your male doesn't build a nest. I've had it happen with mine more than once and still had successful breeds. As long as he's showing interest in the female, I don't worry about a nest.
I don't use the glass chimney when breeding. I use a clear plastic cup with a lid on it until the female shows all signs of being ready. I then remove the lid, but keep her in the cup. When she's completely ready, she jumps out of the cup on her own. I tried the chimney, but my poor females would end up getting ripped to shreds. I've found that by letting her jump out of the cup on her own, that they breed in a matter of hours and there isn't as much fin nipping unless I'm breeding an overly aggressive male (or female in some cases). You'll find what works best for you and remember not all breeds are going to be textbook or follow any advice that you are given. They all have their own personalities and you'll learn from each experience.
Live foods are best for the babies, but don't fret if you don't have any. I panicked with my first breed because my microworm culture didn't produce and I was positive that they wouldn't survive, but you can use liquid frye food, micropowders and smashed hard boiled egg yokes to feed them. They may not grow as quickly, but they will still be healthy. If you use any of these, I would recommend putting one snail in the tank after the babies are free swimming to help keep the tank clean. I got this recommendation from another breeder when I complained about how filthy the bottom of the tank always seemed to get, even with live food, and I've been impressed with the difference since I've started using snails.
