The first one is way to similar all the way up( which doesn't really work for a windmill in my opinion)
The second, the bridge is fine, just the roof part is a bit too tall and would look a bit better if you add somewhat of a half ark as it goes up( not the thing on the top of it)
The third one ( I sadly don't know what it is) is way to repetitive with the windowish area.
And the last one seems fine just not sure what it is
Sorry if I offended you/ and or seemed like I was just blowing out my frustrations on you and your builds. And if I was really vague...man that's a lot of ands