You make really good points of course.
We don't want to dump on one set of people and there have been many who did far worse in world history. When really studied closely the Puritans don't come off well. But the same can be true of almost any group of people. People are flawed, we have good and we have bad.
The problem with the Puritans as I see it was they came to the colonies and set up a theocratic dictatorship. This was a bad idea that was going to fail. Rowdy free-thinking, contrary by nature English men and women weren't compliant subjects in England, they certainly weren't going to transform by crossing the ocean and relocating to another continent.
It's a shame that the Puritans weren't defeated and denounced by the British colonies and later the US government, like they were in England.
After the Restoration in England Puritanical ideas were almost thoroughly swept aside as far as having any influence in government and culture. Not so in the colonies.
I'm in my 70s too. Your riff on separatists gave me a chuckle, even read it aloud to my husband.
Even though I have a natural distaste for the Puritan's thought and actions, their blood still runs in my veins. I try not to dwell on them too much. They accomplished some good but they came to North America and began slaughtering whales (my ancestors were heavily involved in the whaling "industry"), trafficking in slaves and executing their population for witchcraft.
That's not to say I hold the Puritans responsible for slavery or the slave trade which was then and is now a worldwide practice.