Hi Karsten , many thanks...

EvalutateCurves is the ability to insert one or more points
on a curve, and to have as output, the point, the frame
oriented on point into a curve;
therefore a "blend "between your Path_Array and GetCvrS frame

In Extrusions Node you could use the Vector
for direction plus a distance, and , optionally possibly to
draft on the faces-

About Grasshopper, I think you have been Unfortunate to watch the Video ! ! !
Grasshopper , in my opinion , is the First and I still unbeaten program for
Parametric modeling Nodal-
The program is full of fans, and believe me, ABSOLUTELY worth it for you to give a view to the Forum
http://www.grasshopper3d.com
and the impressive number of plug-ins dedicated to it
http://www.food4rhino.com
I think you should perhaps get some inspiration
from the big old GH-

In any case, I am attaching some picture of how are the nodes
in Grasshopper related to Evalutate Curves and output Vector , and Curve length

Good work, and have a good day
Best
al