I owned one of these when I was a kid. I thought how cool to own a mini-lobster in my tank!! Well he was nothing but trouble!!
I had a rock set up as a cave and the crayfish would have daily battles with my catfish over the cave. So they do appreciate a hiding spot. Also I never observed him preying on my fish but I did see him attack sick fish. He also used to uproot my live plants and eat the roots. I believe it was Cambomba, not sure but it was annoying to wake up in the morning and see my plants chewed up and floating every few days.
In my opinion they are very cool but just be mindful of his tankmates and decor choices. He was very active and not a picky eater in the least. He molted very quickly and actually grew pretty large,maybe 5 or 6 inches. That's including his claws by the way.
As far as company I'm not sure as I only kept one and I owned a ten gallon at the time. Also I can't offer any advice as to breeding. I had a community tank and I kept the water neutral, about 78 degrees, and slightly hard.