We found we were fastest when we sailed with less rake than the class norm. Sailing with the class norm our rudders even ventilated at times so we had to sheet out to regain control! With less rake we were seriously fast and went even better to windward. I think we overcomplicate a lot of stuff. Trim rake so the boat tracks straight when going to windward in your dominant conditions and you are fine in my opinion.
Pete, by moving weight forward you get less mast rake quite fast.
I dont advocate sailing with loose shrouds. Your jib tension will hurt in light winds, you want that mast to stand straight all the time and you want to be able to control it. With loose shrouds I find it harder to sail properly, even if the mast is easier to rotate well
