I freehand-routed my own inserts in a playfield design back in 2000...without a CNC. I used a hole saw for saucer shots and a Dremel to dig the shooter groove. I used a jigsaw for the bottom design. It was not fun at all. Some of the insert holes have gaping holes around them, but they are otherwise flush when the inserts are installed. I used the cheap 1/2" crap plywood from Home Depot and retraced a previous playfield to drill out holes for the trough, flippers, switches, etc. Now with the sage wisdom of Pinside, I'll get some good Baltic birch and re-do it properly.
As for the CNC, I may just make insert templates and hand rout it that way, since I don't have CAD. Any word on decent CAD programs on the Mac? I've got an old MacBook from 2008.