Check the tangs for the diamond wires, eventually replace them with new longers ones or at least the rivets if they are old. Also check the rivets on your mast hook, and consider replacing it if it seems underdimensioned.
As long as you dont overdo the downhaul and dont go out twin wiring with a high total crew weight you should be ok.

How much pre-bend you should use is also largely dependent on your mainsail luff curve. If your main is cut for a sideways bend setup, you might well be faster that way.

Pre-bend is definately the way to go, but it's not neccesarily much faster if you dont get the right setup for your sails and crew-weight. Mast stiffness is also important to get the right flexing characteristics, so there are a lot of variables to play around with when you start on this path.


Good luck!