Re: Shooting RAW - White Balance
Granted I do not do much image blending but I have never had problems using auto white balance shooting RAW for landscapes. Certainly in mixed light areas I have to make tweeks in post. more adjustment in areas of shade is usually required and occasionally some creative masking to set differing WB values for different parts of an image.
Overall I find that Auto tends to give me a nice average, but I always try in studio style shots to manually set a WB including setting specific values for camera calibration when shooting people and skin tones. (I don't do a lot of this) For the sporting events auto again is easier to manage for bulk editing and typically gets close to what I want.
If I was doing product or portrait shoots, I would have my WB set as close to what I need during the shoot as opposed to resetting it during post...its just a better workflow.