I only print optically and don't do any scanning so it looks like we're only able to give partial answers. I do quite a bit of Ektar and really like it. You'll definitely get blue shadows with a blue sky if you don't correct for it when exposing the film. The shadows are primarily receiving reflected skylight, which is blue, rather than sunlight. Especially in a snow scene. With an overcast sky, not so much. If the negative is very thin you can't really interpret too much as far as color cast. It's not going to print (optically) well no matter what you do.