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?

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

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.

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

How do flat earthers explain the Earth being stationary? Is this concept considered impossible?

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).

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.

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

In Italy, how do people greet each other when they meet for the first time (e.g., on the street)? What's a good response to that greeting if you're not from Italy or don't speak Italian fluently yet?

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

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

In response to A2A:

Is it possible that my TF caused a kundalini awakening in another person? He is famous because He is a singer. We have not met physically yet, but I have gone through kundalini awakening and DNOTS and their ongoing. I have also had soul recognition so I know for sure that He is my Divine Counterpart and I do not have any doubts about it. But it is indeed perplexing that somebody had an awakening at the physical level because of Him. Is it a test for me? I have a mixture of feelings. On one hand I marvelled at Him and empathised with the person and on the other, I doubt if this just a test for me. I would appreciate your pov. Thank you for much.

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).