The blue acara is south american, and the labs and zebras are mbuna (african). I don't know much about the acara, but from what I've read, they prefer peaceful tank mates, and need a meatier diet, both of which don't mix well with mbuna who are aggressive and mostly need an herbiverous diet (labs are the exception).
So I would rehome the acara, not sure about the eels, have heard some success storys, while others have been killed by the mbuna. I'd definately add more labs, they do best in larger groups of 5 or more, and then pick another species of mbuna and add 1m/3-4f.