Nice...the waterfalls are interesting. You will have to work on exposure a bit, so that the skies aren't 'bright' and trust me, it's hard. I know.
Maybe use bracketed shots, so that you have three images...one a little overexposed, one underexposed, and one correctly exposed, and you can make it work. Or, you could always get some filters, as time and money allows. Circular Polarizer, or ND Grad filters, and the list goes on and on.
Nice job, though, I do like the waterfalls (#2 & 4)...and congrats on the camera.