Personally, I would find dropping aimed shot to be a huge DPS loss, especially since you are moving in pretty much all of the fights in ICC particularly. I suppose in the first 4 bosses there is minimal moving overall in the fight, but you'd really have to try hard not to move much at all. Having that extra instant is so so so handy I find, especially in fights like professor putricide! Also good for a nice quick MD, couple of instants and the tank has a good amount of threat to go on; though this is most certainly an afterthought.
dropping aimed shot for focused fire is clever i think. you loose the 6% damage advantage when using multi, but what you gain seems more powerful - 1% for anything. the only thing i would change in this spec: go for max TotH instead of resourcefulness. everytime i use the onlinecalculation it seems to be a dps-loss over other things, an in a raid situation i often delay BA because ES is (nearly) ready and so minimum 2secs are wasted.