I have researched the Cornish families for 15 years. The assertion that James came from Perranzabuloe has been around for some years.
I have the IGI records and can find no record of a James born in this Parish in this period. Is there any record to indicate that he originated from Cornwall?
The Cornish were primarily involved in mining and farming at this time. Apart from those involved in maritime trades at the time there is little evidence of migration until the collapse of the tin mining industry in the 1860's. The early Mayflower migrants originated from the Devon port of Plymouth. The Mayflower sailed from Southampton to Plymouth and then to America. The origins of the migration were primarily based on religion. Since the majority of Cornwall followed the "State" religion (Church of England formerly RC before Henry VIII) this was not an issue. Very few followed more radical protestant faiths.
My own belief is that James possibly originated from the Yorkshire Oates clan. There is evidence that some of these families were wealthy. It is unlikely that James would have qualified as a lawyer at that time without some wealth behind him. He would probably have been connected with the business families involved with sugar and tobacco imports from this region at that time. The people involved with this region were wealthy businessmen running shipping involved in the slave/sugar/tobacco trade at the time.