Skyak.
I've looked at your drawing.
The sail area seems inadequate for your design goals.
I see maybe 12 to 15 sf of sail. That is not enough for anything but a good breeze of maybe ten to twelve mph.
The leeway preventor seems too far aft as well.
As for my 'Triyak' design, neither of the floats will touch the water when it is level. Only their keels will.
This will definitely compromise paddling to some degree, but the paddling would be done mostly on dead calm days.
Sail assisted paddling and/or paddle assisted sailing would be more the order of the day, typically.
Every design is a compromise, and I thought getting rid of the troublesome dagger board in exchange for a bit more surface area, when paddling, was a worthy exchange.
As for my other design, it has the shape it has for reasons other than simplicity. As it heels, the bow and stern sections, that aren't even in the water, when the boat is level, add a considerable amount of righting moment. Also, as the boat heels, a "V' section meets the water, with one ruler straight side to leeward and curved side to windward. It is conceiveble that this boat could sail to windward without its side mounted dagger board. Once I build the prototype, I will try it.
Failing that, it should track quite well when hard pressed under sail, but maneuver quite readily when upright, as when changing tacks.
As for your design, I'd consider extending the mast considerably, maybe as much as three to five feet. Then you would end up with more like 20 to 25sf of sail, and the Center of area (CA) would be further aft as well, making the boat more likely to round up, when over pressed, rather than charge down wind.
Sharpii,
the picture is a bit off. The luff looks like less than half the boat length, but it will be 6 foot. I hope to keep this luff length because 6' is the limit to 'standard shipping'.
My target sail area is 14sf but honestly I would love to add more. The limitation is the righting moment of the kayak as a monohull. I don't know how much experience you have with kayaks but if you are judging based on other boats you will be way off. The positive is that kayaks take very little to push in displacement mode ~3lb thrust, so the need should fit the limit. Comparing to what is currently offered, 14sf is big. Upwind kayak sails are mostly about 9sf and the 'large' ones are only 16sf -meant for tandems and trimaran setups.
http://www.falconsails.com/design/index.php
http://www.kayaksailor.com/store/pc/viewcategories.asp?idcategory=2
My sail has a much lower center of effort and the MSTAR is beamier than most kayaks so maybe I can up the area. Actually, I originally designed the rig for the purpose of determining how much sail area I wanted on my 14ft kayak. The more I thought about it, the more interested I got.