"felony, and breach of the peace" covers any kind of criminal activity.
look, we all know the intent of this article - to stop the executive from preventing the function of the legislature, by arresting its members without cause, or for cause related to operations of the body itself.
it does not apply to this case.
Sure it does. Congress could not function properly if the Congress Critters could not take bribes. Or so they seem to think at any rate.