Yes. He's done as good a job as he can, given the circumstances.
No, and he should be replaced by a true conservative, not a RINO.
No, and he should be replaced by a more moderate speaker.
Unless Republicans are utterly convinced that they will get more accomplished with another candidate (which I sincerely doubt), I would say no-Boehner should not be replaced. Asking him to be replaced with a moderate is also likewise foolish.
"No religion is true, but some religion, any religion, is politically necessary. Law and morality are insufficient for the large majority of men. Obedience to the law and to the morals are insufficient for making men happy. […]Law and morality are therefore in need of being supplemented by divine rewards and punishments."
If the left thinks Boehner needs to be replaced by a moderate then he must be doing a pretty good job. Nothing makes the left's job more easy than a moderate Republican.