please tell me how to use an iPhone with Verizon, or for that matter, how I keep Apple from remotely disabling FStream if they decide to do so.
Complaining that you can't use your iPhone with Verizon is like complaining that you can't get Sirius on your AM transistor radio. It's a different type of signal... why is this so hard to grasp? If you want to brand one as "proprietary", it would be Verizon, since the majority of the world is using GSM not CDMA, and the iPhone is usable on any GSM network. Apple didn't develop some magical protocol that only the iPhone uses.
Second, Apple cannot disable FStream. The most they can do is remove it from the app store. There was never any conclusive proof either way, but the conclusion most people reached is that since the disable code was stored in the CoreLocation framework, it was for disabling apps from using location services.