Sorry for thread necromancy, but...
c) why a civilisation in a FTL world would have monarchy and nobility.
He doesn't. All three (starfaring from the get-go) monarchies we had seen in any details so far were founded like that:
1) Someone installed a "monarchy" somewhere basically because it sounded cool (Gustav Andermann, naturally, Manticore Colony Inc. original shareholders, arguably, and WEB Du Havel argument isn't that far from it.)
2)???
3) Profit! It's suddenly not just a corporation with a cool-sounding name for shares, but really monarchy...
As for the preaching... In the recent books, thanks, I suspect, to working with Eric Flint thre is less of it, not more.
Spoiler:
Almost all blunders of the liberals both Manty and Haven's were retconned as caused by Mesan sabotage in some way. Not the ideal solution, but...
What really ruined the series for me was that not only Weber got Protection From Editors, but he also got quite vocal fandom of rivet-counters. And, since unlike historical fiction, the only data are from the books themselves, they encourage him to over-explain everything. (While still stealthily moving wormhole junctions around...)
And if ANY ONE OTHER state in the Honorverse would have that idiotic "Vice-President should be from the Opposition" arrangement, I'm going to burn the offending book and post the video of the act. I don't care how convernient for plotting that is, it's moronic. Even an American conservative, who firmly doublethinks that The Framers left all sorts of hidden messages in the Constitution if it's plainly and unambiguously read by a non-activist court, should realize that for such a provision to become a law the entire legislature has to be stoned.