Just an afterthought, if you do find yourself over powered and youre not able to reduce sail, get as much on the cunningham and outhaul as you can. Its sounds all backwards , but you want your mainsail as flat as a board, not nice and bellied and round.
By increasing tension on your cunningham, you bring the draft of the main forward. The centre of power of the mainsail moves toward the mast.
By increasing tension on your outhaul, you are flattening the main and making it less rounded, which is less aerodynamically efficient.
The above makes a surprising amount of difference, give it a try one day. You will be able to see the draft of the mainsail move forward.

If you imagine a giant reaching out and pushing on your main. You don't want him pushing on the middle/back of the main and at right angles, it will round up the boat and make it heel. If you get our helpful giant to push on the front of the main and at a slight angle forwards, the boat wont round up as much or heel anywhere near as far. And the boat goes forward, not sideways.
Make sense?