I have a few conclusions on all this, or rather "known unknowns":

1) It is biologically impossible for Francis Dingley to be the father of the John Dingley of Lynn Massachusetts and Marshfield. Francis was born in 1550 and married a contemporary, Elizabeth Bigge. John Dingley who married Sarah was born in 1608.
2) Henry Dingley, son of Francis and Elizabeth, was born in 1582 and married Joan Pitt. I believe he is the father of the John that moved to Massachusetts in the the 1630s and was born in 1608. I can't definitively prove that link, however.
3) Not sure how meaningful it is whether Sarah was a Chillingsworth or not.
Would love others' thoughts on this.