[cobrashoch]

OLD DOG - A switch on the positive side would still kill the power to the engine electronics/coil, so that makes no difference, the engine would still die. Even one wire alternators make ground through the mounting brackets/bolts on the engine. Yes you are correct- if you somehow kept the alternator running regardless of if the engine is running, it will produce power.
That said, the negitive side is still the simplest side to switch without having to run a dual harness in a car if you go on the positive side.