How would Margaery have done as Robert's Queen?

[Tyrosh Lannister]

36 minutes ago, Craving Peaches said:

It's not entirely clear. The text implies that the plan was for Robert to fall in love with Margaery and set Cersei aside for her, but I would assume there was more to it than that.

But Robert cannot simply set aside Cersei. If he did, this would cause an uproar throughout the seven kingdoms, insulting Cersei and House Lannister. Considering GRRMs Westeros is very much influenced by medieval history, particularly England, and the concepts of marriage, infidelity, and chastity portrayed in Westerosi culture reflect this (copy pasted this bit from another thread). Tywin would rebel or at least work towards Robert's downfall.

[Craving Peaches]

1 hour ago, Tyrosh Lannister said:

But Robert cannot simply set aside Cersei. If he did, this would cause an uproar throughout the seven kingdoms, insulting Cersei and House Lannister. Considering GRRMs Westeros is very much influenced by medieval history, particularly England, and the concepts of marriage, infidelity, and chastity portrayed in Westerosi culture reflect this (copy pasted this bit from another thread). Tywin would rebel or at least work towards Robert's downfall.

It wasn't the best plan but I doubt anyone except the Lannisters would be bothered enough to rebel. The Reach would be on Robert's side, Dorne hates the Lannisters, the North with Eddard in charge is unlikely to do anything, Riverlands aren't likely either. 

[DominusNovus]

Plus, if Renly even gets one part of his plan off the ground (no idea what “step 1” for him was), Stannis can come in and point out that the current heirs are bastards and the queen is guilty of treason.

He might hold both Mace and Renly in contempt, but they have given him cover to reveal what he knows without looking like its self-serving.