There are a couple of answers to this question. Live rock is considered live for several reasons. These include housing benificial living bacteria, housing live sea life and containing living benificial coralline algae. The reason that people tell you to get your Alk & Calcium up is that high levels in those two areas will help existing corraline algae grow (existing = added to the tank via live rock or products like garf grunge). The reason that all aquarist strive to get good coralline growth is that coralline competes with other detramental algae for food in your tank (which helps to keep your water clean). If the corraline is using up the food source (phospates, silcates, etc) that other algae thrives on, then those other pain in the butt algaes can't grow and the tank stays clean and healthy. This is why so many young tanks struggle with algae problems. When you look at really healthy systems they are usually covered with coralline on the rocks, walls, powerheads etc. I wouldn't recommend the iodine because it can cause algae problems in itself. Some aquarist use it to promote growth/healthy attachment of corals but it is debatable that it is needed at all. For right now while your tank is young you definitely don't need it. If you want some ideas on what to expect from your new tank check out the begginers section of my website (listed below) and my pictue pages. Good luck!
