I'd like to submit my suggestion for the easiest way to cut a keg. I found it on a HBT thread, but I can't find it now.
I drew a line with a sharpie along the outside of the keg at the upper weld line. Using an angle grinder, I simply cut horizontally around the keg. It was easy to freehand this - no jig. I put some water into the keg to dampen the noise. Then I used one of those flapper wheels to smoothen the edges.
What I'm left with is a kettle/keggle with a completely open top - no ledge inside to catch stuff.
I wanted to do the more complicated cut where I would cut along the weld line, but leave the handles. On the advice of another HBTer, I purchased a couple gate handles, 4 SS bolts, rubber washers, and locknuts in order to attach a pair of handles near the top.
Respectfully submitted,
Keith