Many thanks for that information. During the last few days you have increased the amount of my knowledge & understanding of Richard Mather many times over.
It seems clear that Richard had stepped out of the C of E and adopted a Presbyterian style of worship which could only result in his being defrocked (sacked) by the C of E. Further, if he had been preaching against King Charles, he would also have faced trial before the Civil Authority and you mentioned sedition. (After all, Charles was the single greatest impediment to Puritan hopes of 'purifying' the Church of England.) In theory the Non Conformity laws passed for the supression of Catholicism could be 'bent' and used against him. There is ample evidence of Quakers being classified as Catholics in order to use the Penal Catholic Laws against them. It is as you have said, he better get out of Dodge. He must have left at his earliest convenience.
(Of course the majority of Puritans continued to worship in the C of E as they had done since 1559. Some Ministers were more pro Puritan than others. Some parts of England contained more Puritans than others. For example puritanism was stronger in South East Lancashire than South West Lancashire which had a significant and influential Roman Catholic minority eg Viscount, Lord Sefton.)
To continue, there seems to be no evidence of any pre planned migration of Lancashire Puritans and individual families and conneted groups of people must have made their own arrangements taking different ships and arriving at Boston on different dates. The theory that Mather organised an en masse migration in Lancashire is therefore dead in the water. However, this is not to say that Mathers own actions did not influence his followers.
As a theory, does the above sound about right? This is important because it impacts on the question, 'did James leave England as a child circa 1635 with his parents or later as an adolescent without his parents'.
Given that we are now discussing 'fine detail' you may care to email me on firstname.lastname@example.org.