Whole lotta questions there Donald. To avoid most of them I would contribute that your vintage of Nacra isn't using the swept spreaders/mast pre-bend/sail-cut-to-match system. So if you were to start pulling 12:1 (you probably currently have 3:1) your results would vary as in your mast would bend in the wrong directions. If all that was greek, this thread may do some splainin. Thread Your spreaders may angle back but that is just for jib clearance. The diamond wires are still loose, and that is what your sail was cut for.

In regards to the crew trimming thaing, that is what the "pro" teams are doing. The skipper focuses on steering fast and the crew is able to use 2 arms and 2 legs to work the mainsheet trim.