Hi Jerry,
In answer to your first question: A balanced rudder, a rudder swept forward until 20% of the rudder area is in front of a line through the pintle axis, will feel neutral, light touch, no matter what the side load on the rudder.
Further discussion:
How did we get where we are? Why are CB trunks on beach cats located at or very close to the shroud chainplates? Answer: Because that is where the CB trunk should be located relative to the CE for the SLOOP rigged sail plan. Now add the spinnaker. Does anything change relative to the CE and CLR locations? I think so and the proof of it being so is that so many boats have lee helm with spinnakers up. What can be done about this? Lean the mast back which moves the spinnaker aft. This moves the whole sail plan CE aft and brings the CE and CLR into better alignment with spinnaker up and may be sufficient to get close to a neutral helm for most spinaker sailing situations. Now, how does this leave the CE/CLR situation without spinnaker or sloop rigged? We have moved the CE well aft from the normal position with the large amount of mast rake. We have unloaded the daggerboard and loaded up the rudder. (Remember the N6.0s, Worrell boats, with spinnakers; the masts were raked way way back. This was the correct trim because they were going to sail all day with spinnakers up.) This will make the rudder prone to stall sailing to windward but once you know it is touchy, you can live with it. A larger rudder would be an improvement in this trim/balance situation because the rudder is carrying a larger side force than it was originally designed for.
This situation of trying control the CE migration due to adding the spinnaker to the sloop rig led me to the CLR design scheme that I call "shared lift". The increased sharing of sail generated side force is being sharred between the centerboard and an oversize rudder. Instead of running a large amount of mast rake to move the CE aft, I have chosen to move the CB trunk forward and run a more normal amount of mast rake. The rudder side load increases with more mast rake or moving the CB trunk forward so the rudder is upsized in both cases. The CB side load has been reduced; it can be downsized. Sizing the centerboard and rudder to match the loads they carry will reduce the drag they generate due to making lift.
Good Sailing,
Bill