The problem is that with transparent bridging you will still need a router if more than one computer will be using the internet connection. But it certainly would work for testing (unless the problem is with the VZ firmware itself). If Verizon uses PPPoE, I don't see how you can do without NAT and DHCP using the PAP2, since that device is not capable of doing the PPPoE login. However, you could let your computer do the login (I believe there is a built-in Windows PPPoE client), and then test the VoIP connection using a soft phone.