A lot of questions with some long answers that would need to follow. My first response if you are going to get into salt, and I am saying this having been in salt only 2 months now, but have learned a lot, both good and bad, I can say this much: Get the biggest tank your wallet can afford for two reasons. 1. You have more room for error. the more gallon you have working for you, the better your chances of survival when you screw up. 2. when you get going, and into it, if you have a small tank, you'll end up wanting a bigger one, and you'll already have spent a mint on all the equipment based on your small tank and will have to re-buy it all over again. Also realize, like I have, that there are many "hidden" costs in saltwater that you never come across in fresh. I've found that if I can get out of my LFS (Local Fish store) without spending more than $50 a trip, than I was lucky. We'll talk more later, but I'm sure others who read this will add their own, or answer more of your questions.