On the Area Light texturing question, this does work in Max, but not in C4D - but, not sure if it works in other engines (and how it's done, if it isn't dropping a bitmap into the Color parameter for the light).
Could be that the light doesn't have a UV map? I can't find a way to apply one, or change projection etc.
As noted, does work if using a CoronaLight material applied to a plane, etc.