From my experience, at schools with rolling admissions, interviewing early definitely helps. But at schools like Yale, Penn, or Duke that send out all acceptances on one day, do you think interviewing early helps or hurts you?
I think that a high MCAT score never hurts, but schools definitely look to see the individual scores. A low score (probably less than an 8 or 9) probabably reflects poorly, even if your overall score is within their range.