Hi Sharif,

For some more info on flat snap see here:
http://moi3d.com/2.0/docs/moi_command_reference11.htm#editframe

re: offset - yeah offset is mostly oriented towards offsetting a planar curve, and the offset happens in the same plane that the curve is in.

It is possible to offset a non-planar curve but it then happens in some pieces that use the construction plane as a frame of reference.

There isn't any way currently to offset a curve that is on a surface and keep it on the surface all in one operation. Sometimes you may want to build a tube around your curve and use the Construct > Curve > Isect command to generate intersection curves between the tube and the surface to get something like that though.

- Michael