Sancho,
Why did Dostoyevsky blank out the street names
I understand there were several reasons ~ first this was done to hide anonymity of real life people who may have inspired the creation of certain particular characters. Second, so that street names that did not exist could not be made up and so that no one could say "couldn't happen there as that street doesn't exist".
Let us say that a certain Smithsky existed. That a character names Jonessky was created and his actions based on those of Smithsky. Had the writer included the actual street name and had there been a socialist guild or lyceum on that block, and that Jonessky frequented that establishment, the censors could have accused the real life Smithsky of treason.
Because of this the writer gave realism to the story while retaining anonymity.
At the same time, if the establishment provided humane services in defiance of the Tsar and his puppet administrators, the censors would have come down on him severely. By not providing the street name, Dostoyevsky protected himself.
There may have been other reasons.
Re Cervantes, I recall a segment in which Sancho Panza took special pride in being Cristiano viejo y rancio. This mean that he was of pure Castilian blood which had not been "tainted" by having Jewish ancestry.
Sefardic Jews are very different from Ashkenazim Jews. They do not generally speak Yiddish which has a German base. They speak Ladino which has a Spanish base. It is undoubtedly the easiest language in Europe to understand and to learn. Other Sefardic Jews used a different language called Haketia.
I can see where someone may suggest that Don Quixote may have represented some form of Jewish ideals though of Sefardic, not Ashkenazim origin. He went on a quest to do daily good (called mitzvah), he sought to promote justice, to serve mankind, to reward good (he promised an island to Sancho Panza for his services), he forswore materialist reward for his own good deeds, and he sought to defeat the wickedness of the world.
When I think about it, Don Q is the antithesis of the mythic wandering Jew - a legendary figure who was forced to wander the earth just like Cain for supposedly mocking Jesus at the crucifixion. This person was punished in that he had to continually travel endlessly until the Messiah returned. He would survive in poverty having no particular trade or home and always be dressed in threadbare drags. Unlike Don Q he does not do good deeds and in some incarnations seeks redemption for his past misdeeds.