Tom:
One of the reasons I like the 9th at EHills is that it fits within the rhythm of the course: it's distinctly different than the rest of the course's par 3s (long, uphill 6th; downhill 13th; level 16th with -- hopefully -- the blind tee utilized for the U.S. Open), and -- along with the 8th -- begins a tough stretch of holes following the relatively easy beginning stretch of the front nine (based on U.S. Amateur scores from a few years ago).
But, as to your original point, EHills may not have a single great hole. Even the 12th has a green that -- give the tumult that proceeds it -- is relatively benign. Was it you that argued great holes need to have great greens? I think 2, 4, 8, 9, and 12 are the best of the bunch there, with 10, 14, 15, and potentially 16 in the running as very good golf holes as well. But great? Probably a fair point.
As for difficult short par 3s without bunkers, I haven't seen too many, but a few come to mind here in Wisconsin -- the 7th at Lawsonia (the boxcar hole), which perhaps isn't short-short, but plays at 161 yds from the tips; and the nifty little 6th at Eau Claire CC, which plays to 134 yds. Both are volcano greens with no bunkering (Lawsonia's left-side bunker has not been restored). The 3rd at the Langford-designed Spring Valley would be another candidate.