running my team of moonkin, spriest, mage x3 I always had the best DPS/Luck on bosses doing the following:

I would make 2 action bars on the druid and make them identical with the exception of my main spam spell. Bar 1 would have a starfire spam macro and bar 2 would have a wrath spam macro.
Both bars had a button in the same location that performed a bar swap between the two. Whenever I saw the moon above my moonkin (or the symbol on pitbull on my mains screen) I would do a quick bar swap and continue spamming.
This worked great until you got enough haste to ditch wrath but I did over 4k dps which still fell short of my arcane mages who did 6k+ in heroic gear.

Just food for thought on the micromanagement.

Edit: spelling