Pointing a powerhead right at the coral is not the best way to go IMO. You want strong, random-intermittent flow, which you can get by pointing the powerheads diagonally towards the front glass or at each other. You don't want the "blast" it, just give it enough to make the polyps move a bit.
As far as lighting, I keep my slimer colony about mid-level. If I move it any higher it starts to brown out (I have 270w of T5ho on my 55gal).