That's not true. CDMA is just one band. The iPhone 5 supports multiple bands, including GSM bands and LTE bands. It also includes a SIM card slot. The iPhone 5 can be unlocked and a new SIM inserted.
Not the iPhone. You can use the SIM internationally but not in the US. Put an AT&T or T-Mobile SIM in your "unlocked" Verizon iPhone and it will not work.
UPDATE: I should also add that if you buy an factory unlocked iPhone from Apple, there is no way to activate it on any CDMA network. CDMA is inherently a locked network.