He wont make it past Law, given that once Room is active there is nothing Starrk can do to stop him.
There is a reason Law is considered one of the more powerful characters in the HST, and its because his "Room" is beyond broken.
@solesamurai: Slicing a frozen Tsunami in half at long range and tagging luffy with a wind blade at long range with his eyes closed. Nothing special given that he is never really pushed to his limits, even during Marineford he suffered little to no fatigue and took no damage despite fighting some powerful people.
Ah, Yea Mihawk hasn't really had to many appearances let alone substantial feats, but from what you said, if he did that effortlessly he would be quite a threat as well.