Eh, it'd be an interesting mix but probably a losing one.
I have BPs with various crayfish, they ignore each other for the most part. But I've attempted (various species on both sides) crays and other cichlids, and it just doesn't end well. The crays often hunt down smaller cichlids, and the cichlids often pick apart small or molting crayfish.
Danios and Gouramis are easily caught by some species of crayfish, and if not caught, they fins are often nipped and torn up regularly by the crays. And plecos are a gamble, since they're bottom dwellers. They'd be a likely reoccurring target.
All of that aside, what's usually sold as the common blue crayfish is P. alleni, which is an aggressive, carnivorous species. It likes to actively hunt, reaches a large size and has a bad temperament. It's not a good addition to a community tank. Now granted, individual temperaments and personalities aren't taken into account here, but overall... it'll doesn't look like something that would work out for you. Try setting up a separate tank for the cray, because they're really awesome to own. ^_^