Upload & Sell: Off
Looking at the photo, before reading that it was multiple ambient exposures, I would have guess flash was used in the foreground due to the way the nearest rock is much brighter than those near it. Flash falls rapidly like that, natural skylight doesn't.
But regardless of how you did it you made the big rock in the foreground unnaturally bright relative others. What the natural light looks like in scene like that is a warm sunset, warm reflection of the sky on the water, but on the shaded side of the rocks opposite the sunset the light will be perceptually cooler because when the sun sets the overhead lighting on the shaded side will be from the sky which is cooler. Everything the foreground will the same level of brightness. More like this...
What did is first take your darkest and lightest exposures layered them, then applied a Levels correction to the lighter one to uniformly lighten all the rocks in the foreground more. Then using screen / multiply / soft light layers I did some selective manipulation to wind up with this...
To add some additional texture to the rocks I did a two stage application of USM...
The reflection of the sky and boats was added by copying the top part of the image, flipping it vertically, then using the Blur > Surface filter to stretch the reflection down. I then used a mask to blend it in around the rocks. I opted to clone out the reflection in the pool of water and spot on the rock because I found them distracting.
When all is said and done it's not a very compelling photograph for me because:
1) The sunset isn't very spectacular
2) The rock in the foreground isn't very interesting
3) The more interesting content — the building and boats — are too small to be seen.
Had there been a Heron or seal on the rock, a boat, kayaker, etc. or anything more interesting than just a rock it would have been a more interesting photo. Had the sunset been spectacular it would have also been more interesting. If it had both all the better. Not saying it's bad, or that I don't like it, just saying what could make it better. Technique aside you need interesting content to tell an interesting story.