On the mainsheet issue, did you have enough sheet to let the traveler all the way out, and also ease the mainsheet?

When you are going downwind in big wind, you don't want the traveler centered, and you also want the daggers way up if you are getting gusts to 30 and not racing toward a mark, but just trying not to flip it. Here's a thought, are you sure there isn't a spare 10 foot piece of line, for the traveler, hanging around somewhere? If not, you can easily add one, then tie it off to the tail of the mainsheet and that should give you 10 more feet of mainsheet, assuming the mainsheet you have now is also going through the traveler car.