Figure 1 indicates that the voltage sampling connection is made across L1 and L2, and no connection to the neutral. Figure 16 shows connection to L1 and AGND via resistor R9 and C7. Shouldn't V2N be connected to L2 via a resistor divider?
Additionally, I am thinking of using the ADE7753. Could I not use two CT's, one on each line, connected in series so that the currents would be the vector sum, thus allowing me to use voltage sampling between L1 and L2?