I dont think a solid trampoline to stiffen up the platform is viable. The loads on a cat are mostly from wracking and the rig, where one hull tries to move in a different direction than the other. Looking at the platform, this means that the mainbeam mostly see torsional loads while the aft beam is trying to bend into an S-shape. You would probably add much more weight (and cost) in the stiff deck than you could remove from the beams. The deck would have to be very thick to make it stiff enough to contribute to platform stiffness.
By "aircraft flooring" I think you mean paper honeycomb cored composite panels. This is the same stuff Marstrøm build boats from.




I'll be happy to upload some saildesigns for comments and discussion. This is one are where there is way too little discussion. Having correct sail trim is one of the major parts of boatspeed, spotting worn out sails is also an important skill. Being able to compare your own sails with the design shape (even if flying shape and design shape differ) is a good thing.
I think writing comprehensive tuning, sailtrim and sailing manuals would be more important for recruiting than an open-source design. If I was to choose a class to start in, having access to this information would be more important for me than having access to open information about how to build the boat.

Btw: I think I prefer to fall on my face/behind/knees on a relatively soft trampoline instead of crushing a solid and expensive panel <img src="http://www.catsailor.com/forums/images/graemlins/laugh.gif" alt="" />