hi!
I don't know if the jaggies come from compression or from a lack of anti aliasing, but they make your shots hard to look at...
it would be interresting shots without them...
the angle you use are very "engaged" or personal, don't really find the word, and I think we can't really discuss about it, as it appears that you worked the composition of the shots and decided to go for such angles... and it actually make your pictures.
your ground textures look to be good, but you may need to tweak your system to render them properly. and neatly.
the settings you used for the weather are not the best from my point of view, despite I like the look of the horizon line in shots 2 and 4, looks like realistic...
to conclude, and despite my critics may look negative, those shots are interresting and very promising... agressive angles, nice colors, and textures... your first priority is to set your system, and/or find a proper method to compress your shots to obtain neat pictures.

vince ;)