For instance, if I want to make a wireframe snowman out of three spheres, I would like to trim the spheres so that only the outermost surfaces are shown. That is, if sphere 1 and sphere 2 overlap, I'd like to delete the overlap region of both spheres. And is there a way to do this automatically with, say a python script, given the coordinates and radii of the spheres? Thanks in advance!
It isn't necessary to use python, you can use Boolean modifiers to do this.
Add a boolean modifier to one of the spheres for every other sphere which intersects with it:
Then apply all the modifiers either by click apply for each one, or by pressing ⎇ AltC > Convert to mesh.