P.S. I still think that it is ok to have all background settings under the Ambient light. To me "World" is a Blender way of doing things and is not necessary to be used in Wings3D. It would save you some work and you could use that time making other things better... 
Edit: Just read your post and it makes sense not to use standard images for lighting. I have never used them for that so I wouldn't miss that option...
Edit2: However maybe some will want to use a standard image as a background without lighting with it??? Maybe that would go under YafaRay Render Options > Background???
oort
Edit: Just read your post and it makes sense not to use standard images for lighting. I have never used them for that so I wouldn't miss that option...
Edit2: However maybe some will want to use a standard image as a background without lighting with it??? Maybe that would go under YafaRay Render Options > Background???
oort