I have a 2048*2048 texture. If I am going to scale it down to 0.250 of its original size (down to 512*512) in WED, is it better (in terms of performance) to simply scale down the original texture in my image editor instead and use the texture at 100% size in WED?

I believe it would be better to resize it yourself. I think it still has to process the original size and texture before it can scale it down..

EDIT: I would anyway.. whats the difference?
EDIT, My EDIT: Unless of coarse this texture will be bigger elsewhere.

Of cource!