Actually, I'd say OCD more than ADD, given his eye for detail and inability to cope with plans falling apart.
Now I love Babs and all, but when you've got all the world's best fighters loaded into your skull, and you can't manage to kill a girl in a wheelchair after getting the drop on her (admittedly a highly skilled one, but he's got the fighting skills of Batman, Lady Shiva, etc.), then you're basically incompetent.
If his intent had been to kill Barbara, yes, that would have been pretty sad. But he wasn't trying to kill her - he was trying to seduce her with the offer of a way to walk again, in exchange for shutting the computers down. In effect, he was pulling a "join me and together we can rule the world" gambit to permanently disable Oracle, because he's the kind of sicko who enjoys corrupting good people.
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. If Batman hadn't shown up when he did and goaded Prometheus into activating his boobytrapped helmet, Barbara likely would have been toast.
And what kind of plans does he have, long term? Kill the JLA, then what?
The long term plan is "fight any and all superheroes" as a way to meet the overall goal of "Fight Good". Kinda like how "fighting all criminals" is Batman's way of meeting his overall goal of "Make my city safe." It's an unattainable goal as there's no way to truly make a city 100% safe or to permanently destroy all good in the world. But they can make a dent...
Second stringer? Compared to the likes of Sinestro, Lex Luthor, or Hank Henshaw? You betcha.
Well, everyone is a second stringer compared to Luthor and Sinestro.