Well Mr.JQL that's what I did. I used the offset tool from "tools on surface" to offset the curve.
However that the offset curve is not 100% in the same plane as the surface is not really a big problem. It's tolerable. The main problem is that the orientation of all the "array copied" elements is not the same as the underlying curved surface/planes because it's a very tediouse task to rotate them manually in the same plane as the underlying surface/plane.
Which plugins/methodes do you use to array objects along a 3d path?