The title of your post is somewhat misleading.
CDMA radio part of the phone ignored for the moment- These phones are QUAD BAND GSM World Phones.... they should work with *most all if not all GSM carriers.
*As long as GSM frequencies used match, phone should work.
As long as the phone arrives in a "unlocked" condition these phones do not have to be activated with Verizon, if you are using the GSM part of the phone with another carrier. As you mentioned first time you boot the phone it will (or course) want to register itself with the Verizon network, it is a simple matter to configure the phone for GSM use only.
From listings on ~bay...
"THIS PHONE IS UNLOCKED AND WILL WORK WITH ANY GSM SIM CARD AS WELL AS VERIZON.
This phone will require a data plan for use on Verizon.
Unlocked? What does that mean?
For the benefit of those that may not know what "unlocked" means= When carriers offer a phone at a fraction of the retail price of the phone (EG: 1-cent, $29, $49, etc), the phone is SUBSIDY locked to that carrier. What this means is a locked phone will ONLY accept the SIM CHIP from that carrier.
(EG Verizon in this case) Once unlocked it will accept SIM's from any carrier.
The above applies the GSM part of the phone. I do not know if the CDMA part of the phone is "unlocked" for use with other carriers, or what other carriers use CDMA beyond Verizon and Sprint in the USA. As unlocking usually pertains to GSM SIM SLOT accepting a sim from another carrier than phone was originally sold (and locked to) - I'd bet the CDMA part of the phone is locked to Verizon.
AT&T (USA)= GSM
T-Mobile - worldwide=GSM