I am not an expert either. But here goes.
1) Subject matter is epic. Composition isn't bad though I am not a fan of the person's boots in the shot. Focus seems off to me. Somewhat blurred.
2) Composition is good though I am having a hard time deciding if the horizon is straight. Exposure may need to be bumped. Also seems like the focus is off on this, also blurred.
3) Subject matter is pretty standard, if the light/shadow play was more pronounced it would be more exciting. Also suffering from a focal issue, also blurred for the majority of the shot.