I love these pics. The color, composition and exposure all look really good to me. I agree with sauce though about the building lookin like it is leaning a little. If the top of the roof was flush with the top of the frame and if the ladder wasnt cut off in the third one.
I like #2 for it's scenic characteristics. It has the bonus of an action element (water) which you might not normally see but is appropriate to the subject. I kinda see the leaning thing. Skew might work but requires a crop after so the roof might be a bit close the top of the frame for it.
Straightness can be a problem with old buildings. I have this problem photographing a lock keepers place near my home, revisited twice now for walkaround pictures. Two timber buidings one behind the other, both out of true with the ground/lock gates! Comparitively these are better than mine.