On the point of more Pokemon getting abilities though, I think that more Pokemon outside of the weather specific types could get abilities. Like you said, there isn't a Pokemon outside of the Ice type that has a Hail ability, and I think more Pokemon like Charizard with Solar Power and Cacturne with Sand Veil would be good. I'm not saying that the current weathers are bad, I just think they could focus on them a bit more, and integrate them into the game more; like making more weather routes and making more it common and usable to more than a few specific Pokemon.
The windy weather condition seems like a good idea, but I also like the idea of a random weather condition that affects each team either randomly, or periodically. Boosting the speed of Flying Types would give them a huge advantage, but it would have to boost both sides, and I don't think it should double their speed like Tailwind does. A 1.5x boost would be good, the same way that Rain and Sun boost their types by 1.5x.
The prospect of a randomised condition would be cool as well, like a distortion world or something, where each team randomly gets boosts to random stats, or even just like both teams get randomised stats like Moody does.