I want to get couple electric blue lobsters for in my mbuna tank, thee is a pleco but no other bottom dwellers. Is it ok for crayfish to be in with fish and a pleco?

The ones I have are common puffer snack reds so I don't know if the electric blue variety are more behaved but I would lean towards no.

With the pleco, as I'm assuming it's a little guy since most of your tanks are on the smaller side, it may get nipped at. Crayfish can be nippy and mean, and I have seen them snag fish for snackage.

If I were going to keep them as not food, I'd most likely have a few in a tank by themselves.

Ok, thank you. I didnt want to put something in a tank that wasnt compatible with everything

I would recommend against it.