In the very end of things, I think SU should have a command to force making of a face among 4 or more points, even if it would have to create some hidden geometry - break it up to triangles, though I would prefer that it would force the 4 points into a coplanar position upon the user asking it to. Then, even with a non planar face, it should allow people to extrude out that face in some kind of user defined or automatically calculated direction (as a mean vector maybe of some geometry ending at those forced-coplanar points definig the face). All this to withing user defined tolerances, I think would work like a charm. As it is now, judging from the number of people running into this problem, it has people chasing their tails for no apparent gain due to perceived "good practices" in some programming paradigm.