Well, the tank looks great so far! I see you've upgraded to a HOB overflow from the power filter -- probably a good idea for a 75g tank. Good choice.
I'm not, nor will I EVER be, the Tang Police, but just so you know you will have to move that blue hippo out of the tank and into a longer tank eventually. A 75 will probably be fine for a year or two, however. Watch him for stress-induced HLLE. For the time being I'm thinking he'll be OK, and your bioload is nice and small for this tank....even better for the tang. Good on you if that was the intent!
One question: how are you liking that Jebo skimmer? I've heard mixed reactions, but I was looking at getting it for a friend's 55g setup. SHe's on a budget, so i was tempted. Is it working for you? Do you have issues with the cup overflowing and/or not producing enough foam? Does the water level have to stay constant? OK, I'm shutting up now.
But back to your tank.....I'm really liking what you're doing with it so far. You should start thinking of some easy to maintain corals!!