The criteria should always be that as long as the ballot can be attributed to a voter it should be counted.  In probably over 99% of cases where a street suffix or a generational identifier has been ommitted, the voter can be indentified through other means. 

If there are two people with the same name in a household and they both requested ballots and one did not put the suffix on it, but the other did.  It is obvious which is which.  If neither did, and they both return, it is irrelevant.  In the really unlikely case that two people with the same name apply for ballots and only one returns it and that person ommits the generational identifier and it cannot be ascertained through an identifier on the return label code, the registrar can compare the signatures.

Similiarly, the chance that two people with identical names on two streets with the same name, return their ballots and both ommit the street suffix and the county not does not have the ability to indentify them through return labels and signatures is so remote as to be irrelevant.

As long as a ballot can be traced back to the original voter in some way it should be counted rather than rejected based on sweeping, arbitrary rules.