Great questions. Let me see if I can clarify a little bit for you.
2) I think if I understand you correctly, you are wanting to basically create a non-visible Viz so that you can use it to just extract data from your view. In that case, the best advice is to create a <div> element that is positioned off-screen or maybe stacked below something else in the z-order. The Viz has to be visible, though, so you can't just use "display: none".