U
He actually quite specifically told Tywin to go fuck himself and that he wanted to stay in the Kingsguard because he was tired of people saying that he had shit for honour and didn't want to break yet another oath (like that one about protecting the king instead of stabbing him). Tywin was powerful enough to ignore whatever laws he wanted whenever it was convenient to do so but that doesn't change what the law actually is ans Cersei isn't handing over her title.
There is established precedent for leaving the Kingsguard with Ser Baristan's dismissal. And Ser Jamie had agreed with Lord Tywin to reclaim the heirship of Casterly Rock before Tywin's death. Therefore I will reserve judgment regarding Abbott until we find out Jamie's title in season five.When Jaime joined the Kingsguard, he gave up all of his titles and claims, so he is no longer the heir to Casterly Rock. With Tyrion being found guilty of Tywin's murder, he lost his claims as well, so Cersei is now the official Lady of Casterly Rock. If she dies, the title would pass to Tommen, who would probably have someone run it for him while he's on the throne, the same way that Robert had Renly in charge of Storm's End. Over time (and barring various zombie invasions or his getting eaten by a dragon), it would likely pass to a second son while his first son keeps the throne.
And since you're trying to be all Johnnie Cochran like, care to explain Ser Loras since he is the heir to Highgarden as well as a knight?
He actually quite specifically told Tywin to go fuck himself and that he wanted to stay in the Kingsguard because he was tired of people saying that he had shit for honour and didn't want to break yet another oath (like that one about protecting the king instead of stabbing him). Tywin was powerful enough to ignore whatever laws he wanted whenever it was convenient to do so but that doesn't change what the law actually is ans Cersei isn't handing over her title.