as to lighting T5HO are all well and nice, but if you decide you want to add sps down the road MH (or LEDs) are the way to go IMHO. Also in my experience watts per gallon don't really mean much in reefing, it's the PAR values that are important.
When introducing corals, some people dip or QT them, I personally don't because I don't have the room or light for a QT coral tank. you don't have to QT if the coral are from a reliable source (LFS with good, parasite free tanks or fellow reefer with the same) Also some drip acclimate coral too, again I don't I feel that corals aren't as sensitive to rapid changes especially when they are coming from bad water.
One thing that I do is acclimate new coral to my light, placing it first in the bottom of my tank, and slowly moving it up to where I want it.