Why is my dough sweaty?
I'm fairly certain the sugar, being hydroscopic, is drawing moisture out of the dough as well as the air and dissolving, which produces the sweat you've noticed. It doesn't help that kouign-amann dough is chilled before rolling with the sugar, which means you could have straight-up condensation happening as well. It's not just the metal pan, but the dough itself that's chilled. 

I don't think you can avoid it-except by working very quickly once you've started rolling the sugar into your dough.

As to your texture being breadier, it's hard to say. It could be you need to do a couple more folds to get thinner layers. It could be that they're overproofing before you toss them in the oven. Or the ovens not hot enough maybe... Like I said, it's hard to say. But when I've made kouign-amann, they were very soft in the center, with crunchy outer layers and a salty caramel shell. So it's equally possibly that there is no problem. Breadiness is subjective after all. 

One thing I do know is that if you want a more crisp pie crust, you can replace part of the butter with shortening or lard, both of which are lower moisture than butter. I don't know if it's even worth considering for kouign-amann, but it might be an interesting experiment anyway. A pie crust is different from a yeast bread obviously, so I'm really not sure what effect it would have overall, but my guess would be that the outer layers would be a hot flakier/crisper.