Is this a good set-up?

I think 2-3 mollies would be pretty crowded in a 10 gallon, I would only put 2 or 3 in a 20 gallon tank. You may have territorial problems with the two gouramis, too. I would suggest one gourami, some sort of small schooling fish that looks like mollies, and then two or three cories (cat fish) Although I don' t know much about chinese algae eaters, any sort of pleco- even the small ones- need at least 20 gallons.