Thoughts on Shawn

Brandon has definitely grown on me over the last couple of years. There is still something about Jasoon Cook, when he came back briefly for what must have been the 50th anniversary, it felt like come home again. But Brandon's earned his stripes as the character. I honestly don't know what I'd want to see him do on the show, as part of the program for both Shawn and Belle was has been the lack of proper character development. Back in the day, I rather liked the idea of Shawn following in his uncle Mickey's footsteps, in wanting to become a lawyer; which they ditched during all that bullshit with Jan. I know they've made him a CSI, but I don't feel like that was ever really earned. It was just arbitrary thing, like making Belle a lawyer, after I think I initially having her want to be a nurse (after first planning on being a fashion designer, because why not?).

I've honestly never cared for Martha as Belle. She's just never worked for me and I wouldn't mind them trying a recast, though t this point I don't expect them to.
I don't expect Kirsten back either, though that might be interesting to see. Overall Belle's development has probably been worse than Shawn's. He at least has had some history before being aged to the teen scene. And I think he's been more involved at least as a secondary character in his parents stories even after becoming an adult, more so than Belle has.

It may sound drastic, but my own personal thought would to get rid of Clair. And mean permanently.
It's extreme, I know; and I initially had this thought before they aged her, but aging her only seems to have made things worse.
The characters were way too young to introduce a child between them. Which isn't to say, of course, that people as young as they were or younger don't have children or shouldn't have children, but strictly from a story perspective it was a mistake. The writers hadn't gone to the trouble of establishing who these characters were in their own right and adding a child did nothing to help. It wasn't a teen pregnancy story, it wasn't anything more than a contrived way of cementing the idea that these two characters were supposed to be together just because. The only thing remotely good to come out of that was the relationship between "Robo-John" and Claire when she was played by Alina Foley. They had a great dynamic, which I don't think they ever revisited after aging Claire again.
And then aging Claire as much as they did this last time, even though it's been a few years, plus the psychotic break has just compounding one bad decision with another. She was way too fucking old to be Shawn and Belle's daughter, regardless however old the actors are. The Last Blast streaming series reaffirmed that Shawn and Belle have been out of high school less than 20 years; so they should not have a daughter in her 20s.

Get rid of her, or retcon the shit out of her and make her a little girl again somehow. Say that "Claire" was some cousin they had become guardian of or something and their actual daughter has been away at boarding school or in the bathroom and she's really only like 12 or 13 at most.
But mostly I'd say get rid of her and start Shawn and Belle off fresh.