Not bad at all.
#1 The juxtaposition is excellent. However, the subject is sooo strong I would have taken it a little more off center to make the image more dynamic, and perhaps made it smaller in the frame. Bright yellow against dark red is a very strong contrast and can hold it's own. The center of the image is the strongest, so if you place a a strong subject there, there is little draw for the eye to explore the rest of the scene which may contain interesting surprises. This is the reasoning behind the rule of thirds. While I don't think there is anything magical about those 4 specific points in the image that the RoT creates, the general idea is to create an image that isn't static.
#2 I really like the scene, there is plenty of interest and you did a good job of filling the frame with relating subjects. The light is soft and directional. However, I do not like the position of the camera. I would like to see the camera down level with the gourds, or the sign. If you do this, you must be even more careful of your background though, as the sky or buildings or people are more likely to intrude. Also, the white balance is a bit on the blue side. Especially for a fall subject, I'd like to see it warmed up a bit.
#3 This is the weakest of the 3. To me, the strongest thing in the image is the unnaturally deep blue sky. It could be the barn, and it could be the tall tree, but both of those are cut off by the frame, so maybe it's the sky? You see, I'm not sure what you want me to see here.