How do the Sola Scrptura folks react to the Dead Sea Scrolls and other more recent discoveries of ancient Biblical texts not among those canonized by Martin Luther?

The New Testament was established as part of creating a universal (catholic) interpretation for all Christians.

If you study, you will find passages in the Orthodox Bible, not in the Catholic.

Since the Bible is a collection of writings (literally what biblia means), you will even find that while Matthew and Luke have genealogies, Paul wrote to Titus and Timothy not to pursue foolish genealogies.

Why do some men like anal sex?

However, if one is using the Bible as a premise and traditions, how does one evaluate discrepancies between the two, as traditions are interpretations of Bible passages as their claim for validation.

Just as there are a few discrepancies between the Masoretic and Samaritan Torahs.

Even Jesus questioned how the Messiah was David's son.

Are female judges more lenient than male ones?

Actually, Luther was influenced by the books of the Masoretic Tanakh and did, originally, include the Apocrypha.

The influence of the Christian Old Testament was the Septuagint, which predates Jesus. Luther, also maintained the Septuagint philosophy of law, history, poetry and prophets, in ordering, while the Tanakh followed Torah, prophets (Nevi'im) and writings (Ketuvim).

In response to A2A:

Was there a British ‘genocide’ of Aboriginal Australians?

Nuda Scriptira is scripture alone. Sola Scriptura is writings authority over traditions and does not imply Biblical inerrancy (see above in regards to Jesus, and genealogy to David).