I guess the rockwork is up to you and what "look" you prefer. Some people will tell you that you need xx lbs. of live rock per xx gallons of water in the system, but I don't buy that argument for SPS systems. You do need to worry about nutrients though and biological/mechanical filtration. If you plan on running a ULNS SPS system, you could have minimalist rock work but would likely benefit from some form of carbon dosing to help keep nutrients in check (i.e. biopellets or vodka dosing), as well as a good skimmer.
As for the sand bed, do your research there. I would not recommend a deep sand bed in your display - connect it remotely or put it in a fuge in your sump - that way, if it goes south you have it compartmentalized and can deal with it without having to tear down the system. If you have a SSB in your display, plan on vacuuming it periodically with water changes, otherwise it will collect detrius.