Give possibility to sweep function to work with every kind of curve or edge.
It does already, if you mean "trajectory". There are some edge chains and curves where it fails (invalid trajectory) for some stupid reason, then you must use either a Swet Blend, or a Variable Section Sweep (VSS).
I think sweep or rather VSS should fix internally (without user influence) the problems of too small radius or too big curvature and trim the result surface when it has self overlapping.
At the moment we must exclude problematic part of the path use more then one sweep and using several other methods close the gap and merge all surfaces at the end - this is really unpleasant part of designer's life...