Sailcut CAD can not export directly to jpg or pdf, but converting a DXF file to jpeg or pdf should be trivial. The developers are accomodating to new ideas, so if you asked they would probably implement it.


Building a 'test' sail in paper is probably a good idea before you get experience with how your designed shapes will set on the boat. If you hand cut, it's a lot of work tough..
For a spi, paper is to stiff, so I will prefer to do a 1:10 model for experimental work.


The method Mike describes are somewhat documented in "The sailmakers apprentice" that you mentioned. But the reference work is Jeremy Howard-Williams work "Sails". Sailrite also have some good booklets on this method, I have heard.
The main problem with the old method, is how to get the twist you want into the sail. The design software takes care of all broadseaming calculations, so you get the twist and shape you designed into the sail.

You dont need multiple bands of webbing, just align the webbing with the major load path. If you want multiple bands (like for the mainsheet/outhaul on a mainsail), just cut off the corner and use a shacle that you leave on the sail. Use a S-hook on your boom to just hook up the boom to the sail when rigging/de-rigging (saves time). Or get a shacle and grind off the tip so you dont need to turn it to make it enter fully. Use a bungee to secure it when sailing.
Or you could go all the way, and make the webbing long enough to pass around your boom..
This is part of the fun, use your creativity and do it like you want to.