[Dingo]

The HOB and small powerhead, no media is good. Do not use a biowheel as it really adds no benefit and adds the risk of extra nitrates. I have aragonite on my bottom, you can use sand if you like, but you won't wwant it blowing around. I would avoid CC because it eventually turns into a detrius trap. 1 to 1.5 lbs live rock/gallon for filtration is all you need.

You can use NO lighting if you like, but you will be happier with the color of a small PC setup. Also, Coralline will grow better under PC if you like the look.

For shrimp, I would highly recommend a group or three or more sexy shrimp. They hang together, have interesting behavior, and are small, so crowding is not an issue. Hunt down Caja, she's got some and loves them.

CBS are pretty tough characters, and will probably kill most anything else you put in the tank.

If you are going away for long periods of time, I would either have the tank covered to minimize evaporation, or have an autotopoff system. Autotopoffs are, IMO, the single best thing to put on a nano, because topping off every day is a PITA.