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?

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

In response to A2A:

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

What smell will you never forget?

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.

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

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.

Why don't I get sleep at nights?

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).

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

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

What is it like to be a Christian in Iran?

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).