LTA's can burry there foot in the sand, its normal. In fact they would prefer to have more than 2 inches of sand. I would say watch it, but leave it alone for now while it seeks out a location that it prefers with medium current and the best lighting conditions.
Feeding can be with = silversides, krill, mysis shrimp, plankton, chopped shrimp, scallops, formula 1 or even a home made food that you prepare. Beth has a reciepe somewhere. You can us a turkey baster to gently squirt some food into the central disk.
Feed 1 or 2 times per week.
As a bottom dweller you will need lighting that can penitrate deep enough for the anemone to take advantage of.