To eliminate the confusions that both Verizon Wireless customers and customer care staff members might have about certain topics: sending and receiving multimedia messages does not count against your data plan. It only counts against your texting plan. I know this because I talked with a customer care staff member who knows about this stuff. Also (for customers), in order to set up Apple Calls on Other Devices to where your iPhone does not have to be turned on or nearby, you have to have a postpaid account. If you have a prepaid account, the iPhone has to be nearby and turned on. I tried it myself. I am so sorry for the previous misinformation. Please forgive me, everyone.
Also, the locking of devices to Verizon Wireless's network is only for devices that were purchased on or after the day of the device unlocking policy amendment. The Verizon Wireless Customer Care Staff have told me this.