Man, so much work. Really killing it. Those anime paint over things look fun, must try it myself. I think it would be a really good learning activity.
Your enviro's are suffering from the same problem mine did for a VERY long time. The values are pretty far off. The best way I got through this (of course this is just the method I used) is to get a whole bunch of enviro images, they dont have to be big, infact 500px is plenty, and spend 20min and do a study in B&W.
Vary it up by sometimes converting the image to B&W before the study, then try and do it from coloured images, but make yours black and white. This will help you work out the local values for each of the different hues in the spectrum.
The only time you really have to be picky is try and get images that arent edited with filters and are pretty close to stock.
For example, this one is edited:
http://mrfarts.deviantart.com/art/Hope-i...-439710129
There is no way in hell real life looks like this. It would be awesome, for a while if it did, but that much constant saturation would probably make me vomit.
This one however, is pretty close to standard (or at least withing a reasonable tolerance since cameras can't actually see what the eye can see, a little editing is normally needed so it doesnt look boring):
http://evelivesey.deviantart.com/art/Lak...-442888499
Of course, choosing where to draw the line is largely your call, and I think over time this line will both change and influence your work.
Keep up the good work man. Can't wait to see more.