Align points (make co-linear) to make surfaces that are coplanar

I am looking for a way to align three or more points in order to create surfaces that begin coplanar and end not coplanar. 

I am creating a form based on this circular grid with the intention of all faces having all straight sections when cut along any radius (the pink set of lines). Essentially, all ruled surfaces with respect to my grid. 

To get an idea of the form I was creating and general dimensions, I used a very simple script to create arcs, intersect them with extrusions of the radiuses, and sweep2 them. 

However, since the arcs are fairly simple curves, I can not make these surfaces tangent (co-planar... essentially appearing to merge into one... they do not need to actually join and merge in rhino, just not present a physical crease).

All along I've had the intention of making the rail curves more complex than arcs to achieve this, through probably IntrpCrv, but I want to maintain as much simplicity as possible. 

I cannot for the life of me figure out how to make these surfaces coplanar -before- they hit the end of the form without going into rhino and manually drawing every single section and connecting them which honestly solves nothing because I can't maintain a smooth curve manually while trying to make several surfaces tangent at multiple points. 

Any help would be much appreciated!