Just an update: Got the whole transmission replaced. They also seemed to have replaced the front driver seat and driver side door panel since they smeared grease all over it. There's a bit of grease (but barely noticeable) throughout (steering wheel, carpet, driver side seat spotting). The mechanic also left a his socket wrench in the engine bay rolling around on the plastic underbody. I've notified Infiniti Consumer Affairs and the dealership, but doesn't seem like there's much they're willing to do at this point.
End of venting. Despite these problems, I'm going to try and enjoy the ride.