Bent stick first: I don't know. But I've seen the figure appear several times in megaliths. There is a standing stone on Machrie Moor eg that is bent in the same way. I explain it as the early days of British geometry - there was deep superstition connected with what was actually scientific research. I think that power was invoked by alignment and that if you could incorporate two alignments in the same structure, by a kink, then you could accumulate more magical power.
I've measured the Smithills stone rows to an accuracy of about plus or minus two and a half degrees. An engineer would laugh at that accuracy - or lack of it - but there are unknowns, in the field, that can alter the results by this amount no matter how accurately the azimuths are defined. This is atmospheric refraction, which varies according to barometric pressure, atmospheric pollution and something else I've forgotten. It's like trying to measure a loaf of bread with a ruler - the only true test is to taste it. With the Smithills stone rows this means watching for the moon at the dates they were built to record.
I'd like to see photographs of sun and moon sets from these newly found monuments. As well as the lunar points one of them gives a good indication of the sunset on the shortest day - this one's on Winter Hill ! - and the Thurstones give a good indication of the sunrise on both May Day and Lammas Day. I hope to capture the mayday sunrise this year - bet it rains ! These four lunar observatories also help explain why some Boltonians are quite weird.