All very good points, Murph. I wouldn't think tacking the rudder on an 18 would be that critical. Since you are getting lift off of the daggerboards as well as the leeward rudder, I would think that would take some of the pressure off the weather rudder.
As for Hakan's idea, whenever I have tried lifting the weather rudder while at full speed, I have been unsuccessful. The rudder is too loaded or something to pop up. Doing so from the wire sounds even more difficult.
Mike Madge just emailed me to tell me he (Hakan) keeps his rudders real loose. Maybe that will make a difference. I will have to experiment this spring.
The Marine Tex idea on the cams sounds interesting. I would have to see if it is per class rules. What do you do? Do you fill in the hollow when the cam is locked about 1/2 way? If so, does it make the rudders kick up easier (and inadvertently)?