I know they have broken up more than once, but I don’t recall any others than the 2004 (university) and 2007 ones. There is so much gossip out there, but quite honestly not much with any substance. Very much like the M „hazing incident“.
Long term relationships go through up and downs. That’s not really surprising. And even ONS or affairs aren’t exactly out of the ordinary. I am also not sure K has given up on her personality. What we see is a VERY curated version of her. But if she is doing things for getting the Crown than this part of her personality. Either she hides things in public or she just isn’t it. She could be an absolute badass, ruling her family and husband with an iron fist for all I know. I can absolutely see her being perfect for this because the stuff that matters to her might not be the passionate, romantic, all rosy relationship but a rational partnership, wealth, power, security, connections and all of this guaranteed for her children and children’s children. I won’t judge someone for this. I do think W chose her partly because she does fit, her family is extremely important to him and they have a common goal. If both are in agreement it’s all fine.
I do agree that the royal life does probably not have much allure if you already move in the same circles, and have a carefree life without the pressure and scrutiny.
Regarding the visits- if the Walses were smart they would be very visible without having much more on sight engagements. Those engagements need quite some planning and are a huge stress for the places that are visited as well. But carefully planned “private” outings will bring them on the first page as well. Visiting places, school run, shopping…. To balance this out, they can have their stuff pen letters to their patronages or charities, people/research groups that achieved something, which will always find their way into the public. They fail at exploiting their staff efficiently. They could appear extremely busy without actually doing much more.