Bill,
Yeah, I like the curved traveller a lot, though it would be tough/expensive to retrofit this boat with one. The current system provides the same constant downforce on the clew, even when the clew is not directly over the mainsheet. And I can see that not having those 2 line up will stress the boom more than a direct connection between mainsheet and clew. But I think I'm committed to this system, and I don't think it'll be difficult to build a boom that can easily handle the forces generated by the misalignment of clew and mainsheet.
I think the major compression forces are produced by the outhaul resisting the desire of the clew to move forward(towards the mast) when pressure is applied to the body of the sail. Without the outhaul pressure the sail would want to bag out to leeward, which would entail the clew moving forward. This was very noticable on the original main of the Reynolds 21, which was boomless. When it blew over 15 kts, it bagged seriously, even with the mainsheet attached the the furthest forward hole in the clew plate. How does the N 6.0 get around that?
Thanks for the input, I'm still trying to come up with clear pictures of the forces involved here, and it reall y helps to get a bunch of different perspectives!

Dave
And all of this is theoretical, it's clear that there are signifcant compression forces here, evidenced by the flexing experienced.