allright lets take these one at a time:
LR: if its cured you do not need to go through the curing process again. And cyclilng you can put your sand in there you dont have to buy live sand. if you can get a couple of cupfulls of sand from and allready established tank and put in your tank that will do. and you can drop a piece of cocktail shrimp in the tank and that will help kick it off.
Preparing SW, you want to make sure that it is completely mixed. most people stick a powerhead int he bucket for a bit to make sure its mixed and then add it to the tank. you want to make sure the salinity is the same and the temp is pretty close too. And adding top off you DONOT want to add saltwater. when water evaporates the salt does not. just top off with RODI water.
and with sps corals yes you can keep them with t5's. some may have to go to the top and some can go mid range. just make sure if they are highlight or med light sps.
As for an anenome, you can keep an anenome with your lights. but you want to make sure your tank is stable. anenome's require very good water quality. as long as you have good light and good water you can keep an anenome. and I would not mix clown species they are very aggressive towards diff species.
you could add like a 6line wrasse or a lawnmowerblenny but keep the fish small, look into diff gobies like watchman or panda gobies.
and in the cycle process you can add a clown, they are a very hardy fish and work great for cycling a tank. when your parameters level out and the tank stabilized you can start to add stock. it really doesnt matter what you add but dont add too much at o ne time you want to do this gradual so the tank does not overload and crash. and as for feeding fish and corals you can go to like foster n smith or marine depot live and most of their items have feeding instruction on the specific critter. I hope I got all your ?'s answered.
GREG