What are the overall goals of the 505 class with the rule changes?
Only when you answer that question can you properly discuss how to change the rules.
Is the aim to stay current with modern materials?
Is the aim to change the class because people are afraid it is becoming obsolete from a performance standpoint?
Without answering this question first, I believe the class will get into trouble with any rule changes.
Like it or not rule changes will result in perceived performance differences and if an upgrade to a $3000 mast or a new $15,000 hull is perceived as needed it will effect the class. The changes may or may not be needed but the Class should clearly state what their goals are from the beginning.
Having separate North American rules and having only this elite 5 that go to the Worlds with the ability to change their boats to be competitive on the worlds level is absolute rubbish in my mind and a sure fire way to kill the class in the US. What chance would there be of running a World Championship in North America? (Tom is referring to Ali Meller's point about racing at a higher weight in NA to keep older boats competitive in NA.)
I also think that the class should think long and hard before changing the minimum hull weight or not having one at all. I believe we need a much better reason than it is a hassle to do. To keep a true One-Design class takes some hassles.
To say it is obsolete is very short sighted. Having been in the boat building business, I believe not having a minimum hull weight will have profound changes that will not be controlled by present boat builders in the class. With a little research you will find that none of the present 505 builders is on the forefront of technology. They are very fragile and not very well capitalized. Remember what Lindsay and Waterat did to Parker, once on the of the largest dinghy builders in the world. Have we really answered the question of whether that helped or hurt the class? All we can say is based on the rules and technology changes at the time the class and its major builders had no control over it. But if there had been no minimum hull weight the changes would have been bigger and more expensive.