this place has a great power and an open secret is probably one worth keeping. i was interested in the foothole next to the "druids font" the stone in the churchyard is quite interesting (note skull and crossbone master masons graves also) how about a theory that the cave beneath the rock that you mention is actually a blocked passage(there are stones in the hole. if you look closely and it is possible to see light through it) and the larger fissure could have been used in shamanic ceremonies possibly to pass through small children. just an idea...the law itself is probably man made which implies that the whole area was in use. Was the churchyard itself the site of a circle? I didnt notice any of the carvings until my second visit but i think youre right.