Your first: you should adjust bthe exposure, so that there is more contrast. You should also move the midtones more to the darker side. Given the high noise level, and the relatively low ISO, I suspect that you did heavy exposure corrections. You will need to address the noise and reduce that to near to zero, without losing sharpness and detail.
With your second, you have about the same issues. You should have "moved" the guy to the right out of the picture, however. If he belonged to your group, that would have been easy, by asking friendly to move a bit to the right. I love the concept, however. You may have a small focussing issue. Even that the ladies' faces are not shown, you may need eventually model releases. You can try without those, however, at a first.
For your third, you definitly have a white balance issue, in addition to the high noise level and the missed focus on the hut. I do not think that you can edit this to a point where it gets acceptable.
ABAMBO | Hard- and Software Engineer | Photographer