I like the aquascaping, it has a nice flow.
The tank is pretty seriously overstocked. The Kuhli will get to 4" or so, the gold loach will get to 6" (and will likely become pretty aggressive before he even gets that big).
I'd move the loaches, gouramis and tetras out to their own tank (preferably a 29g). The livebearers you have in there right now (the guppies and the mollies) would be a pretty good stocking level for a 12g.