Re differences in birth place from census to census.

When dealing with census material and such discrepencies arise, the first thing is to get a photocopy of the original material. For the 1851-71 censuses this means the London copy not the IoM copy.

Remember with census material we are dealing with manually copied material.
I believe the original material shows that copying tended to be done by columns rather than by rows. I have seen several cases where the "birth place" column (in prarticular) appears t have "slipped" by a row part way through a page.

Also, census material is "un-verified". Enumerators were expected to record material as it was given to them.