Check the radios for the model (phonearena should list them all for you).... LG doesn't do 'world' models, so the unlocked one will most likely lack the CDMA radios that you'd need to work fully with Verizon's network.
No you cannot. It might work with other GSM networks but not with CDMA networks. I recently unlocked my G4 using the permannet unlock service from Superunlockcodes.com and I was able to swap with other GSM networks without any problem.