re: To use as a cutting tool for other solids
I could create a smoother surface in AutoCAD by creating the contours as a closed polyline, then raising each one's "Z" level to its proper elevation.
At this point I can use the RULESURF command to create a smooth mesh between each curve and the one above it. Obviously, this is a lot of work, and you're still stuck with just a surface model.
To get the kind of intersection functions you're talking about would probably need a real solid modeler like SolidWorks.