I think this is really good.

1). Actually I like it. I'd add a little more dirt and mud especially inside the orchard and corral, however, and perhaps darken the building roof a good bit.
2) I think you have done a superb job on the steps.
3) I think they are fine.
4) You don't need to paint the stone blocks one at a time; but I can't advise without knowing which programme you use.
5) use your 'gravel desert area' texture heavily on it and it might work.

I don't think the dark clouds over the desert texture in the second image are working - they are too large, regular and shadowy. Perhaps experiment with setting these to overlay, or increasing their detail. Best of all probably would be to create a grainy bumpmap layer and using your dark clouds as the layermap on the grain - might be a bit tricky if you are starting out.