Setting the white, grey and black points is a new thing so I’m appreciative of any feedback you’d care to provide.
By "Setting the white, grey and black points", I assume that you meant setting certain areas to true neutral tones, by using the eye droppers, etc.
More often than not, true neutral tones may not exist in many images, such as yours. Many use the eye droppers to remove an image's casts. But some images' casts, as in yours, are desireable, and should not be removed. Before using the eye droppers (or any other method to achieve a neutral tone), you should evaluate whether true neutral tones do indeed exist in an image first. The exercise is not as simple or intuitive as one may think.
Applying neutral tone corrections to areas that are not true neutral tones will not only change those areas, but will change the whole image, sending you down the wrong path. Kind of like taking the wrong exit on the LA Express. Back tracking can be painful.
You may find this thread helpful.http://photo.net/digital-darkroom-forum/00VNcE