I liked the 1st photo. The edge of the light on the bottom right and the stones on the bottom left built a triangle shape in between which keep my eye in the frame a bit longer. It would have been nice to have a point subject to keep me inside that triangle longer though.
The 2nd photo feels like it should be a horizontal.
The 3rd clipped the top of the falls.
The 4th would be nicer if the camera was lower to draw your eye into the falls with the waterline (in the left corner of the frame) in horizontal position.
The 5th has nice color but the smooth shape is clipped at the top.
You have alot of talent of getting rid of distractions in your frames. I dont see ugly boats, powerlines, stray people, etc... and that's very good. Now that you have only the good elements in the frame, you have to compose them to keep your eyes glued.
Edit: I didn't catch the rest after this post.