My main problem with the show stealing Batman villains is that they're giving Ra's the big bad treatment before fixing their awful treatment of Vertigo. I understand that GA has a weak rogue's gallery, but actually make the few notable rogues he does have into true threats. They did so with Merlyn (Even though, lets face it, he's a bit of a Norman Osborn clone), but haven't done so with Vertigo. Luckily, there's at least two seasons left, so maybe they can rectify this.
Another problem with the Batman copying is Ollie's characterization. He is very much Bruce Wayne lite whereas in the comics, he eventually developed his own distinct persona. I think it would've been cool to see him start off darker before becoming more like the Oliver in the comics, but the Arrow/Flash crossover has convinced me that his characterization may more or less stay the same.