A lot of bits to address, though I have to say up front that I have no expertise in these matters, and David remains a puzzle to me... so I'm afraid insights into his demons are pure conjecture, no evidence. Clearly though, both David and John had growing-up experiences quite unlike mine, seemingly because of intrafamilial circumstances that I can only guess at. I don't think it's very likely that Herbert had a direct hand in that, because he died in 1936 (so David was 11, and they were living in Brockton at the time of Herbert's death) and I don't think there was a lot of back-and-forth between Melrose and Brockton. I remember David telling me about Herbert's shop and how fascinated he was at ages 9 or so to 11 by tools and so on, but I doubt that he ever spent much time with Herbert. 

I too heard the tale of 'inappropriate behavior' by the High Mowing teacher, but didn't make much of that as an element of David's character construction. In the version he told me, he didn't express any anger, and his attitude seemed to me that there had been something positive about the experience (I didn't understand him then, can't figure it out now). 

The sent-away-to-school thing was very different for me. I know that David was sent to Mount Hermon for his 9th grade year (1941 I think), that he was very active in the Radio Club then (which suggests that SOMEhow he'd connected with electronics, but I have no idea how), and that he hated Mount Hermon. High Mowing (which was very new at that time and I think he might have been in the first graduating class in 1945) was marvelous for him: his talents were respected, Mrs Emmett doted on him, and he wasn't confined by having to live at home and keep up the necessary appearances. John had a similarly positive experience, from everything he said to me about it. I think it's likely that David's experiences in his Navy years (1945-46?) are where one might look to find out how the adult person emerged (not that there's any way to find out, but if I was writing a novel I'd use those years as the inflection point). So there he is in Galveston TX, young and really smart and in an elite electronics posting where he could learn anything, and nothing to do in Galveston on a Saturday night except try to get laid... And then back to Cambridge and living at home and starting at Harvard in Fall of 1946. The living at home part required him to keep up those appearances again, to abide by the absolutely unspoken but extremely decorous House Rules as regards female persons... you can see the collision happening in slow motion. A girlfriend at the time was Gwen Very, whom I met 20 years or so ago (at Thanksgiving at Carol Lawson's Virginia farm) and saw again at Alice and Wick's maybe 14 years ago. Gwen allowed as how they were almost engaged, but David wanted sex and she was a Good Girl, so they broke up. Not long after that he hooked up with Judy, about whom he told me that he wanted to "help her" because he knew of her rocky family life and abuse, etc. He also said that she was very different before she had children, that somehow motherhood had run her off the psychical rails... That all sounded pretty self-serving and rehearsed to me at the time, like a tale he'd told himself over and over until he believed it. My own memories of them in the early 1950s are mostly of the chaos of the Reading house, but I also imagine Judy trying and failing to cope with 4 kids and an absent/preoccupied spouse. I don't think there was a lot of love in the equation, in any of the several directions.

As for that story about Carolyn confiding in him her attraction to another man, I can't imagine her doing that. Which doesn't mean that she didn't, just that the Carolyn Blackmer I knew would not have done such a thing. I know it's the case that she had a pretty rocky few years in the late 1940s, but very little evidence to bring to bear on how and why. She suffered bouts of 'arthritis' and I suspect depression, but those were the days before pharmaceutical treatments, and talk therapy of the time would have been Freudian and in any case not the sort of thing one engaged in (or could afford). There were diet things, the most memorable of which was LIVER, which appeared night after night (this might have been for only a week, but I remember it as interminable) and I absolutely hated --smell, taste, texture-- every preparation. Liver Loaf. Pan-fried Liver. Oooooof. They were involved with homeopathy (it was sort of a Swedenborgian thing: the Boerickes were a Philadelphia church family who had a large homeopathic business with the Tafels, also Swedenborgians), though that mode of medical intervention was gone by the time I was 7 or 8. Carolyn was mightily frustrated with the men of the church, and for their part they mostly thought she should shut up and leave them alone to manage the affairs of the church. And here we're talking the Church in the national organization sense. She, for her part, was a scholar of Swedenborg's writings and had a lot of ideas. I suspect that they felt threatened... Anyway, there's Franklin, President of the Theological School (1937-1953), then President of the national organization (1953-1955), then put out to pasture as co-pastor at the Wayfarer's Chapel in Palos Verdes. He was a quiet and hard-working administrator, but together they made a number of enemies within the church.

Anyway, Carolyn went back to school in 1946 or so, at the School of Education at Harvard, and when she got her Ed.M. degree, took a job as Dean of Guidance at Bradford Junior College (traveling by train between North Station and Bradford every morning). This got her out of the role as President's Wife and provided a whole new population to express her care and attention upon, between about 1949 and 1955. She was appreciated and respected in that role as she wasn't in the Theological School crowd, and she positively bloomed. Doing the math, I was born in 1943. By the time I have memories to string together into coherence, Carolyn was away most days studying and then working, and I was watched over by a succession of graduate student couples who lived in the basement apartment of the big house on Quincy Street (that's right in the heart of Harvard's campus). That was great for me, and I never felt in the least unappreciated --hung out with my father a lot, went on his errands with him, read a million books, was the adored and precocious later-life child (Mother and Father were 44 when I was born...). I had none of the challenges and restrictions that I imagine David and John might have experienced when Carolyn was trying to cope with the limitations of a role (minister's wife) she hated. And oh yes, Mother and Father were indeed the terms of address and reference for everybody but Alice, for whom Father was Daddy. And her part in all of this is probably very significant, though as I said she said that she "didn't remember" and there's nobody alive now to ask for more details. You might find it interesting and useful to hunt up a copy of Robert W. White's Lives in Progress (3rd edition, 1975, for the updates), which was THE standard text in Psychology of Personality courses in a lot of colleges between about 1952 and the mid-1970s (and so is available used via Amazon, pretty cheap). It follows (via interviews every few years) the lives and development of 3 people, 2 men and a woman. The woman, Joyce Kingsley IS Alice. Or Alice IS Joyce Kingsley. She was recruited by Robert White when she was a Radcliffe undergraduate. Makes very interesting reading once you know you're reading about the life of someone you know.

Anyhow, they didn't send me away to school. When we left Andover and went to California in 1956 (I was just going into 8th grade) the schools in Los Angeles were awful, and the opportunity (indirectly via Swedenborgians) to go to a private school in Palos Verdes came up. It was a wonderful place, and I fit right in despite being from Back East and clueless about Southern California culture. When Franklin and Carolyn went to Urbana OH in 1958, to rescue Urbana College from itself (Carolyn was appointed Dean of Studies), I was invited by the headmistress to stay at Chadwick, all expenses paid, for the last 3 years of high school. So I didn't have to figure out how to live in Urbana OH, and I saw them basically at Christmas (at Alice and Wick's) and for maybe a week or so in summers. I escaped, I suppose, and never had to deal with house rules or necessary appearances after I was 15. A relief to all. My memories of the general atmosphere of growing up do in fact have a lot of love in them, and a degree of security of who and what I was that I'm not sure either David or John ever felt.

Enough of this for now... maybe I'll think of other stuff to add when I read over your message again.