You've heard it before and it sounds like a cop-out but it's true: there are no answers to these questions. The only way to approach it is to consider your individual situation. If you have good grades, a Science paper, a PhD and a 210 step 1, your step 1 isn't going to matter much. As for program rankings, it is somewhat easier to come up with fellowship/subspecialty ranks, but even these wouldn't be universally agreed upon. But if you have identified heme as your fellowship of choice, then go to a program that has famous heme people. But if you're like most people and don't know, then going to a place that has the most good fellowships makes sense.