Whoah... Angua has said repeatedly that she loves Carrot, and even explained why - "because he's kind without trying to prove anything - that's just how he is! - but he can also be nasty when the occasion demands it" (quote combined from bits of Jingo and the Fifth Elephant). Both she and Carrot have been willing to make ridiculous sacrifices for each other. Both she and Carrot had doubts about each other (Angua about 10 times more frequently), that they eventually overcame. I'd say they're way past the "on the brink of running away" thing
Ditto Sam and Sybil. Their marriage started out more or less as a joke, and then gradually solidified. It's something Pterry keeps reminding you of, by dropping little hints here and there... like the fact that Sybil keeps knitting socks, even though she can't turn a heel worth anything, and Sam keeps wearing the aforementioned socks without complaint... even though the soles are thick enough to serve as a plot device at one point in "Thud!"
All in all, I'd say that Pterry's lesson is more along the lines of "the course of true love never ran smooth" or something like that
. That no relationship is perfect, but then, the imperfections are what offsets the good parts, and makes them shine.
Just out of curiosity - what would you have changed, Banana
?