Ok, well unless it is a mix of female and male Dwarf Gouramis, you're going to need to rehome some. Dwarg Gouramis can be excessively territorial to the point where Males tend to be aggressive to other gouramis from different breeds.
From what I've heart, Algae eaters tend to get too big for that size. I'd wait to see if someone can confirm/deny this. Also, I'm not so sure about cichlids being with the rest of the fish. The Tetra, platy, and Gouramis can usually flourish alright in a community tank as long as ratios (such as one male to two females or one male gourami per tank) are met. Cichlids, from what I've heard, require slightly different paremeters when it comes to their tank set up. I think the big ones are PH, temp, and water hardness.
Also, have you tested the water parameters? I'm not sure about the bioload. Can you give us exact numbers of each species?
Sorry, If I'm a bit spastic in typing. My brain works faster than my fingers can type haha.