I can't help much with the "washouts" of sky and colors in trees, but on first glance I think you will get a lot of "buy a circular polarizer" comments as polarization tends to cut out glare.
But, as for composition, I would think if the sky is not that attractive, AND you are wanting to pull our attention to the scenic view, I would think you could all but cut out the sky. In other words crop out that sky and let the horizon sit about 10% below the very top of the image.
Then, if I could shoot your shot, I would have composed it that way IN CAMERA and spot meter the trees or river. Maybe bracket your shots by using the auto-bracketing feature (provided you have one) or taking the shot automatically and looking at the f/stop setting and shutter speed, and adjusting the shutter speed a little slower and then a little faster for 3 shots of varying exposure. Then, go home and play with all three and make a memory note of which you tend to like better....a little overexposed or a little underexposed. For color, I tend to shoot -2/3 stops underexposed to get the richest color I can.
In other words, say you want an f/stop of f/11. You shoot the shot with the shutter the camera gives you from Av mode..say a shutter speed of 1/500. Then, you switch to manual (M) and remember to set the f/stop to f/11. Set your shutter to 1/500 and give it a click, two, or three slower and take another shot. Then, click back to 1/500 and click the same number of clicks faster and take another shot. You have three exposures that are fairly close together, and can play with them back home on the computer.
That said, pano's 2 and 5 look pretty well colored to me for the daylight you were shooting in. Oops, that's another thing. Tend to shoot at daybreak or sunset when possible. The lower angle of the sun gives better lighting, color, and more dramatic effects with shadows and what not.
Hope that helped.
, 50D, [17-40mm f/4
