Is it possible to break multiple overlaping circles (think Vinn diagram) at their intersections into arcs? Is there a lisp file that can do this? Or is this a simple command? (AutoCad is new to me.)
Yes I am sure someone out there has a lisp routine that will simplify the process. You can do a Google search for lisp+break, but until you find one here is the long way around. select the circle you wish to break. Select "br"(for break)"f" for firstpoint then an offseet amount i.e. .0625. Autocad will not allow an arc to be a full 360° so if you want to maintain the illusion of 360° then just offset by a extreme amount ( .ooo1)
Create 2 circles, select trim, pick both circles, press return, click each circle outside the intersection of both circles but still on the periphery of the circle.
You can do that faster than loading up a lisp routine !