Your last sentence asks about Nicholas and Benjamin, and Mary Getchell (also, Gatchell).
There is no direct proof that Nicholas and Abraham were son/father.In fact, there is some speculation that they could have been brothers.The fact that Nicolas was born in England abt 1705, and Abraham remarried to Jemima Davis in 1714, says that Jemima would have been the one who raised him, and then, Nicolas would have surely been in Haverhill Mass, where Abraham and Jemima were living and having thier children.
In 1730, he married Mary Hunt Ingersoll.She was born Nov 12, 1708, and was the daughter of Benjamin and Mary (Hunt) Ingersoll.The Falmouth, ME records show some of their children having been born there, as Mary H. Ingersoll's family was at Back Cove, and that is where Soffee says that he settled.That appears to be correct.
I also found that Nicolas had purchased and then resold land at Small Point, on Phippsburg, ME.I have transcribed a copy of the deed, which shows the land was purchased by Nicolas from Benjamin Fanueil of Boston (of Fanueil Hall/Quincy Market fame), that was in 1758.The land was resold not too long after, by the mid 1760s.
Benjamin was born on Feb 15, 1729 or 1730, at Falmouth, ME (now Portland).He died on Nov 29, 1793 in Bowdoinham, ME.