I did get NATS disabled remotely by someone. It didn't do all the magic I hoped it would do, but I guess it's still nice to have one less thing that can get screwed up on the car. I still have the fobgina, and it still appears to be necessary to put the key in there to turn on the ignition and start the engine with the stock button. Who knows if maybe *anyone*'s key does that now, though.
Re: basic ignition, it sounds like you *could* in theory get rid of the keyfob sensor at that point, but only if you did some custom wiring to your own on/start buttons and ditched the stock one (because the BCM controls the engine start button, and NATS disable is just the ECU - the BCM still cares about they keyfob if you wanna operate that switch...).
I was also hoping it would allow me to unplug and remove the steering lock unit (which is currently disabled with the fuse-pull hack anyways), but it doesn't do that either. If I unplug the steering lock unit I get a little Key icon warning light on the gauges and it refuses to turn on the ignition.
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Also, I had my first major screwup with the unwiring of the car. When I was removing a bunch of little modules from under the dash (e.g. fob sensors, TPMS receiver), I removed one too many little black boxes. I didn't realize until a couple of days later during a test-drive what went wrong. One of those little black boxes under the passenger dash is the power steering controller
I still have tails on the box itself and on the various places it was wired to, but I'll have to run new lengths of wire to hook it back up. Could've been much worse I guess, and everything else has gone pretty smooth so far. Still have days of work ahead of me to get the harness stuff all wrapped back up nicely.