#1 - I don't think anyone else mentioned this, but the horizon isn't level. I apologize because this is a big pet peeve of mine. I'm also guilty of it. Half the landscape shots I take I end up having to straighten. Even though it isn't level, leveling it might actually make the woman and child look like they are leaning, strangely enough, because it appears that they are both standing straight. So, I might experiment with the straightening to see what it does to the shot.
#2 - I really like this shot. The composition is great even though it isn't your typical "rule of thirds" style composition. The child's head being cut off actually adds to the shot I think by drawing your eye down to what she's focusing on (the sand castle).
#3 - I personally am not a fan of selective coloring. Were those huts that color, or did you add the color? I think the shot would look better as a pure B&W, and I'd actually like to see it like that.