Three separate points there, and they deserve separate answers.
On the thousand boulders. That's exactly the null hypothesis, so I tested against it rather than around it. I generated 2,000 random sets of eleven points within the same patch of ground defined by the stones and ran the same 144-foot test on each. The real arrangement hits clean multiples of 144 three to four times more often than chance, and the result holds at every tolerance I tried. More telling is the control: the diagonals of the cross produce no clean multiples at all. Noise doesn't distinguish between a meaningful line and a meaningless one — that the axes hold while the diagonals fail is the part I'd find hard to explain as chance.
On Nolan moving stones. Agreed, and my book says so. He relocated several before satellite positioning existed, which is why I worked from Amundsen's 2003 GPS measurements rather than anything later, (noone in the modern search published coordinates) and why four of my eleven positions are flagged as derived rather than located. It's a real limitation and it's declared.
On Boulder C, I think the sea level runs the other way. Nova Scotia has among the highest rates of relative sea-level rise on the Atlantic seaboard, for two reasons rather than one — the ocean is rising and the province is still subsiding after the ice sheet left. That's well over a metre since 1200. So the shoreline then stood further out, and a stone on today's waterline was further inland and higher above the tide than it is now. The erosion exposing it is recent because the water has been coming to it.
That said, if Ritcey's geological evidence is published somewhere I'd genuinely like to read it — and if he's arguing the stone was buried in till rather than submerged, that's a different claim and sea level wouldn't answer it.