Your livestock list looks good, although I would very strongly recommend not adding the mandarin, and instead choosing another nano-appropriate goby. Mandarins require a steady diet of copapods, and your system is too small to produce and sustain a population large enough to keep your mandarin healthy. I think the only mandarins that should go into nanos are those that readily accept prepared foods, which in itself is pretty rare. There are lots of other cool gobies that you might be just as happy with.
Here is a
nano fish list. Take a look at them and the profiles, maybe you can find something else!
Good luck!