Hi Andy, and welcome to the AA forum!
I can't advise you on the questions you asked, since the largest tank I ever had was a 125 Saltwater only. As of now, I am strictly FW
. My advice would be to go the saltwater forum and post your questions there, since the really knowledgeable aquarists re. reef and lighting, etc. are going to be over there. But I am glad you joined, and welcome again.