#3 and #4 are not novels.
I liked, enjoyed may be not quite the word, "Night thoughts of a classical physicist".
There are quite a number of novels, plays etc. about the Manhattan project. Not totally and not meant to be totally fiction. There is "The Man who would be God", a personal swipe. I've read 2 or 3 times "Principles of American Nuclear Chemistry".
Top class literature is Primo Levi's "The Periodic System" - it's chemistry so broaden your horizons!
Regarding which, the phrase "he's one of those physicists who thinks Science is a branch of physics" occurs, I think, in the novel "Mine own exceutioner" by Nigel Balchin. More famous by the same author is "The small
back room", both made into films, perhaps a bit distant is location and time from what you are looking for, and are supposedly middlebrow novels that actually are not that comfortable.
"The Quest" by CP Snow I remember as much better than any others of his, a quite convincing situationing in the research process as well as in the scientific society of his time and place; the narrator seems close to the author and his most vivid character is a very thin disguise of a scientist all informed readers would identify without hesitation. It is scientific-political while his others are more so, much concerned with the "
corridors of power" in government and academia, somewhat sychophantically. Again some of it relates to the Manhattan project and its follow-on.
The two italicised phrases from the book titles have also entered common language.
I thought that Swiss guy who dramatised Bohr and Heisenberg etc. then and elsewhere has done the world no great favour, but it's up for discussion.