Gee, the tool merchants drool over jobs like this! Your choice is between fussing & cussing every inch of the way - or buying lots of new toys!
Get the best Rotozip you can find, and fit it with solid carbide milling cutters. Might get a cordless one too, for the odd job off in a dark corner. Finally, there is a 'sled' that lets you use the rotozip like a saber saw. There's no better way to cut plaster & lath.
Belay that. There IS a better way - and the tools are finally making their way over from Europe. "Flex" is one maker of a tool that can be best described as a circular saw with two blades spaces about 3/4" apart. Just what you want for cutting in your chases in the walls.
However you do it, you'll want to invest in BOTH a drywall-specific vacuum (with HEPA filter, maybe $150) AND an air cleaner (fan with a filter to catch airborn dust).
I can't see doing a 'complete rewire' without your having to add several new circuits, etc.
For making simple holes there's nothing that beats an impact driver. Milwaukee even makes a big one (7/16" hex collet) for driving the selfeed bits through lumber.
The multi-master is divine for the occasional slot or rectangular hole in plaster & lath.
