Point of realism: unless the sky island is magically anchored, windmills will be less effective than on land, as the island will be blown by the wind and eventually move with it, which will literally take the wind out of the mill's sails. It'd need some calculations to see how bad the situation is. It looks like this island could be loosely approximated as a 100m diameter sphere, and for convenience, I'll assume it has an average density the same as the Earth's crust. This gives us (4/3)pi(5000 cm)^3 times 2.83 g/cm^3 = about 1.5 x 10^9 kg of mass. That's hefty enough it could take awhile to get up to speed, but it also has a lot of surface area for the wind to push on. It will matter which way the wind is blowing, since the island is irregular. If the mills were turned to catch wind coming along the long axis of the island they'd be getting the best results, as those winds would bring the island up to speed more slowly, but let's see how much of an issue it is. For purposes of calculation, I'm going to assume a wind pushing against a cross-section with the area of a 100m diameter circle, or pi(100m)^2, close enough to 30,000 square meters for our approximation. The force exerted by the wind is going to vary with the square of its speed, so I'll just pick a speed of a 25 miles per hour, or 11 m/s. The other factors in converting this to Newtons per square meter of pressure are a bit more than one, but I'll round down to one partly for simplicity and also to account for some inefficiencies in the wind accelerating the island (it isn't a perfect sail). This gives us a wind pressure of 121 N/m^2.

121 N/m^2 x 30,000 m^2 = 3,630,000 N. Newtons are kg-m/s^2, so divide by the mass of the island to get acceleration: 3,630,000 N / 1.5 x 10^9 kg = 0.00242 m/s^2. That's a small number, but seconds are a small unit of time. If this acceleration was constant, the island would be going about 8.7 m/s by the end of the first hour, but the relative speed of the wind and therefore the pressure from it, will decrease as the island starts moving with it. Still, it looks as it the issue will be a practical concern, not simply a theoretical one.

That aside, it is a very nice map and the top and side view match up very well (although the sheep are invisible from above... probably some defense mechanism against sky wolves, and there seems to be a size change in the tree and building at location 7, although I really had to look at the match ups to notice it). I really appreciate that the shadows match up. It's very nicely drawn and I probably shouldn't be worrying about the physics of sky islands.