Regarding sail materials:
I have offered up this reference before, and stand by it: "Historic Ship Models" by Wolfram zu Mondfeld. He recommends white cotton cambric, or other very thin close woven materials. The intent is to reduce the weave in scale so it is hardly noticeable. Wash the material in warm water first to make it more pliable. He also gives a method for dyeing the sails with tea to achieve the correct colour.
Use paper templates, kind of like sewing patterns. Don't forget accessories such as the bolt ropes, reef bands, etc. as they will show up in your scale.
I like to furl my sails as I think this looks better than a static model under full sail but this is only my opinion. Another idea is to brail up the lower sails so as not to impede the view of the deck (upon which you have lavished such care and attention, right?).
Ships under sail always look better (I think) with the yards braced around as well.
Let me know how you make out ...
Regards.