I'll fill in some answers here........ yes, you need an adapter (about $138 delivered each) for each LED but only 1 controller which can control over 500 lights inline (I think) with splitters and such. Go to the Gavita.com webite, everything is explained pretty well there. I just traded (and bought) everything I need to set up everything, I just need to find the time and energy to make the connections get to it so check my thread for updates.
Gavita recommends 24-36 inches height over the canopy in veg, and 18 inches in flowering. I played with the height the bit, at 100% power, my last grow. I'd say 36 inches 1st 2 weeks, 30 inches week 3 and 24-28 inches the rest of veg......... and 18 inches throughout flowering but I still went up and down a few inches there too. No matter what, make sure you have enough air flow around the plants and canopy to avoid issues.
There is really no advantage to move the lights closer than stated heights, unless you are cranking in the CO2 at high amounts and the strain reacts well to it. No need to over push it though, you'll just end up with the plants over reacting in bad ways. Stay within the limits, it will work out fine. I also ended up fertilizing about 30% in the ppm, so I went lower not higher. The Cal/Mag was run pretty high also.
I'll look into my IM's here, but I get them all the time.