I feel like your goal will strike a chord with the sailing community. Many sailors venture to sea with little resources and need to be as sustainable as possible. However, their goals and requirements are a bit different from yours. For example, many sailors are willing to burn gasoline to generate power. Still, I think it's a good plan.
Do you consider plastic sustainable? If not, what will your boat be made out of? Wood is probably the most sustainable material for boat construction, as it is biodegradable and easily produced and worked without the use of toxic chemicals. On the other hand, frequently toxic chemicals are involved with its maintenance (toxic chemicals are also involved in the maintenance of fiberglass, or, well, just about everything on a boat).
The wing sail thing also does not set well with the idea of sustainability. The whole idea seems to be, with a significant increase in cost, we can acquire a relatively small increase in performance. Do you really need that increase in performance? How much will it cost to maintain and operate? You're talking about fancy electronics to operate it, but the production of electronics involves toxic chemicals, and of course your need more energy to run them. I'm assuming that the electronics will be hooked up to some sort of motor or hydraulic actuators to actually control the wing sail, and this of course requires power as well, probably a lot. It is probably not sustainable to operate such systems on "green" energy alone.
Multihulls. I'm not very familiar with them, but I understand they are more expensive to buy and maintain than monohulls. To me, more expensive basically means less sustainable.
Personally I think you need to reconsider your goals. If you goal is to build a product that you can sell to a wealthy person who wants to appear "green", then you're probably on the right track. If your goal is to produce a system that can support one or more humans for an extended period of time while minimizing consumption on a repeating basis, you need to radically alter your approach.
s/v Laelia - 1978 Pearson 365 ketch
s/v Essorant - 1972 Catalina 27