Actually, I'd say OCD more than ADD, given his eye for detail and inability to cope with plans falling apart.
I'd say ADD. He was constantly on the move, unable to stick with any part of his plan long enough to see it through and make sure it works.
Sure, Barbara put up a fight, but she still wound up dangling from the arm of her clocktower after getting in a good hit on Prometheus.
Maybe, maybe not. He still failed to kill a non-superpowered girl in a wheelchair. And his goal was to eliminate her as a threat. Kill her, seduce her to the darkside, whatever.
The long term plan is "fight any and all superheroes" as a way to meet the overall goal of "Fight Good".
Not impressed. Had he "taken out" the JLA, I don't buy he would have lasted long with every hero on the planet (including Wonder Woman once she found out what he'd done to her mom) after him. Compare him to Batman all you like (not that he's half as good an anti-Batman as Bane or Wrath). Batman has well-written successes. Prometheus managed to take out some Bloodlines characters through the power of bad writing, and Retro. Wow. Retro.
Well, everyone is a second stringer compared to Luthor and Sinestro.
Henshaw? You're joking, right?
Well since you seemed to be suggesting that Prometheus was a "first stringer", I assumed you meant in terms of something other than real world popularity.
Henshaw has Kryptonian-level abilities (in many ways superior to the abilities of Kryptonians) visited death and destruction on many worlds, destroyed worlds, utterly defeated Mongul, obliterated Coast City, took over most of Apokolips (although Darkseid proved too much for him), became Grandmaster of the Manhunters, etc. etc.
He is a planetary-level threat of the highest order. Prometheus is not.