Landscape - Violet Hues

[abovenormphotos]

Hi all, here is a photo that i took over the weekend. i would appreciate any and all critique.

38s f7.1 ISO100

Technique - Was my aperture too large?
Framing - Something a little unsettling. How can I improve?
Post Processing - Used DRI. Blended 2 images for different exposures for water and sky. Does it look natural?

I wanted to capture the colours of the sky during the golden hour, Just before sunrise and also catch the stillness of the water.
I Had a very short window of time. No much cloud movement nor colours of the sky to work with. Only came away with 4 shots in total and only 2 worth keeping. Do advise.

Thanks in advance.