nice planning so far. i'm going to disagree with the others on the refugium light. 6500k is the perfect kelvin for a refugium. you don't want a 10 or 12k lamp because plants don't use that blue light.
fueling nuisance algae is exactly what you are trying to accomplish. chaetomorpha and caulerpa are nuisance algae!
also, i would look into octopus, vertex IN , and bubble magus protein skimmers. these are superior to ASM. ASM was the most efficient skimmer for the money about 5 or 6 years ago. now many other companies are blowing right by them with better construction and more efficient pumps.
i skimmed through this thread and might have missed a thing or two, but i thought i saw the closed loop coming through the bottom of the tank. i would not do this. i would bring the water out through one of the side panels about 3/4 the way up, and the returns i'd have coming over the top. the reason i say to do it this way is because there will be much less things to leak, and also, if the bulkhead leaks on the intake, it won't drain the tank dry before it stops. only the top 1/4 of the tank will be drained.
that 10 gallon fresh water reservoir is probably going to give you about 3 days before you run it dry.