although i just noticed that your having problems with your sky.. in that picture it actually looks kinda cool, i guess if you made some darker and lighter areas to give it a more cloud-like look, it'd look like its about to rain which.. its kidna neat looking ilke that
and since all the rest of the track is blueish, maybe a little darker and if you did what i said, then it'd look even more realistic and ready to rain in the background