Suggestion for new tank

[Oilers]

I admit that I do have MTS (Multiple Tank Syndrome) just like a lot of you on this board. Ever since the tank tour, I've been working on getting myself a second tank and I completed that mission today
The tank is a JBJ 28G nanocube. I am planning a little zoa gardens with a RBTA, a torch and a frogspawn with a few fishes.
1) Blue spotted jawfish. (I've read that the minimum size tank for this fish is 55G. Is that true?)
2) A couple clown fishes
3) Firefish (purple or helfrich)
4) A cleaner shrimp and a fire shrimp
5) A couple snails
Here is I need your help. What else should I add to the tank? I want some small friendly fish that will co-exist with the above fishes. A starfish? How many more can I add with a tank that size?
Also, for the initial set up, can I use the water from my 150G tank so I don't need to cycle the tank? Should I use 1/2 water from the big tank and make up the other half from fresh or should I make up new water totally?
I don't want a sand bed in this tank. What are other alternatives?