They are both CDMA, so I would assume so. I am thinking of switching to the Sprint "Framily" plan, but they dont have a great selection of phones to chose from... =(
No. CDMA carriers will not activate devices that are branded to other carriers. Sprint will not activate Verizon phones, and Verizon will not activate Sprint phones. They use a database of ESNs/MEIDs to determine if the devices have their own branding or not.
In the RARE case where you know someone in one of their departments, I have heard it done before (Someone was using the Sprint HTC WP7 device on Verizon and a 8X on Sprint, I have heard of it before).
You really need to know someone in there WHO would be willing to do it....Trust me, Not easy..