My opinion...
#1 - really interesting photograph, but the foliage on the right is distracting. Suggest cropping it out.
#2 - for me the shot is not enough, what's the subject? My eye looks at the rainbow and naturally travels along it only to find myself stopping at the top wondering where it goes. Might have been better using shorter lens or walking backwards a way.
#3 - lovely image. I feel drawn to follow the track from the lower left and around the valley, in which case a bit more of the left would have been nice, but then the track may disappear even further! Equally, one could follow the stream around the lake to the right and meander up the valley. Nice work! Lots of interest, good to follow around but leaving some suspense. Like it.
#4 - nice view, lovely light. Not sure if the foreground adds anything to the view - try cropping it lengthways.
#5 - nice sunset. Lousy light in valley. Does little for me I'm afraid.