about world space normal maps, they are mostly supposed to be called "object space" normal maps and work well even when animated. the only thing where they really suffer (harder to achieve) is animating on vertex level (deformable...) but if you have some machinery and it is made of different objects, and you animate those…
World space maps are for objects that won't move or transform at all. They are easier for most engines to render without errors in seams, etc, but they just don't work in any engine on characters. This type of asset should be rendered with a tangent space map, and not a world space normal map.
The information a world space map saves is just "pixel X is facing direction Y". That's fine if the object never moves -- you know a texture that is facing east will always face east if the surface it's on doesn't change. But if you were to rotate the model 180 degrees, the surface the texture is on would now be facing…