As my advisor put it, "this is a lottery you want to play. the payout is well over a quarter million dollars (tuition remission and stipend) and your odds are far better." So, who cares what you paid up front. As long as you get in, you wont care in the least.
17 all US. A couple at the very top of PGR, most between 15-30, and a couple near 40. It doesn't feel like overkill at all. I know of too many people with solid applications that have been shut out.
Yeah... I've already gone through this once when I applied for my MA. My impression since then, for what it's worth, is that it's almost all letters and sample. High GPAs obviously have a high corrolation with good letters and strong writing but are not, in themselves, an admission criteria (though they can, of course, prevent one's admission).