I've never heard of several of the things you're mentioning--the meaning of Juvenal's verso pollice is hotly debated. What you call "the perfect" seems to be a misunderstanding of a gesture Quintilian describes, involving using the index fingertip to touch the middle of the thumbnail, a gesture that Quintilian says should be used by the orator to indicate approval and during narration. Quintilian preserves a large number of gestures, which it is useless to list here, many quite complex or used with in situations hardly distinct to us. For example, Quintilian describes a gesture in which the middle finger was pulled back towards the thumb, the hand set in motion, and the shoulders turned slightly towards the hand. This, he says should be used at the beginning of a speech. In factual statements it indicates emphatic conformation that the statement is true; in invective that the speaker is emotionally engaged. A variant of the gesture existed, says Quintilian, where the middle two fingers were used. Moreover, rhe gesture no longer works if the motion of the hand is too great or if the middle finger points at the wrong shoulder. These sorts of intricate hand and body motions were integral parts of oratory, ones which required as much careful though and consideration as the actual words, and Quintilian is full of them