If you use live aragonite in a saltwater tank, do you still need live rock or live coral?

Fish only tank... you don't need coral. It is always better to have live rock, but you don't have to have it. If you treat for parasites, the rock wont be alive anymore. Start without it, learn the basic chemistry, and go from there.

I'd certainly avoid the coral as the lighting needs will add a whole new dimension to both the cost and maintenance of the tank. As for the live rock, I am a big proponent of it for a myriad of reasons. It adds the aesthetics of the tank, it provides natural filtration of the water, it supports a wide variety of organisms that are beneficial to the tank and it gives the fish a more natural environment in which to live, hide and thrive.

As for the live sand, is this live sand that came out of an established tank or bagged sand from a shop labeled and marketed as live sand?

Even with the use of real live sand or live rock I would still encourage you to fully cycle your tank and take the time while waiting for that, to read a book or two on marine aquariums so that your better prepared for things you will likely encounter during your marine fish keeping hobby (the benefits of RO/DI water, how to deal with algae breakouts, nutrient control, etc)

nobody needs coral, coral is another mouth to feed and more crap to clean up.. i think you're confused at to exactly what it is and what it does..

even with live sand you need SOMEthing for the fish to stake a claim on and to feel secure.. lace rock, texas holey rock, even lava rock.. something in there for protection.

god i F(&%ing hate spammers