Whitepages

Are the electoral rolls the most comprehensive source of info?

Not really. Though the data is updated quarterly, the information in the electoral rolls need not be complete because-
a) Only the abbreviated version is made available for online searches; The detailed list can be used only by those having the legal right to do so, such as electoral supervisors.
b) the list might not contain  the  names of voters who choose to "opt-out  from this list .