What an excellent post! Let me see if I can comment without giving too much away. There's a bit more to this land deal, as you mentioned, but nothing you'll find in the history books. This part of the story is pure fiction, other than the fact that there was a lot of development going on up in Idaho.
Elizabeth Danfield strikes me as the kind of person who has lived with a knife over her head for so long (with Alexandra Carmichael) that she's almost immune to fear from it. It's become part of her existence, and something she has to manage, pushing those who have her in their grips, but never too far.
Wade's college choices could certainly change, but I think that anything in the top 20 is within his quality range. The lawyers advised him against doing business in Virginia, but it is still his home state (and DC is his home town), so I don't think that would distract him from attending UVA or Georgetown. He certainly could go to Stanford, but it is generally considered bad form to get your graduate degree and undergraduate degree from the same school. Wade would be quite aware of that, and as it's even more important in academia, JP would certainly counsel him in that regard as well.
I love the way you express the realization on the trauma of aging. You may very well be right about Jeanine.