Most of the folks who seemed to be the most critical of Jews probably had never met a Jew, nor even knew someone who did.
The greater part of the Jewish population in Europe during the period leading up to the Religious Wars (in the 1500s) and the Thirty-Years War (in the 1600s) were expelees from Catholic Spain.
We are not, at that period in history, speaking of millions of people ~ just a few tens of thousands spread over half a dozen countries. More ancient Jewish communities (dating from Roman times) had been destroyed in earlier upheavals.
An interesting film to watch concerning the risks taken by Protestants in this period is "Retour de Martin Guerre" ~ in this movie they hanged a fellow for "violating the marital bed". It's noted at the end, that the priest who sponsored/officiated/blessed that particular hanging was, himself, later on hanged for espousing Protestantism.
It was quite common in the late middle ages to execute people for what we take to be common civil offenses, or for any belief the local nobles might think offensive.
This sort of thing continued in France up to the French Revolution. One of the "causes" in that event were the plethora of "courts" ~ in some jurisdictions a non-noble might well face over 100 different "courts" with authority to put him to trial ~ rather like Iran under the Mullahs!
This is why it's very, very important to find out what context any of these old rants against Jews occurred. Was it really about Jews, or was it about the safety and security of the writer's neck with the word "Jew" serving as a codeword for "RC Priest"?
Or this?
Fourth, I advise that their rabbis be forbidden to teach henceforth on pain of loss of life and limb. For they have justly forfeited the right to such an office by holding the poor Jews captive with the saying of Moses (Deuternomy 17 [:10 ff.]) in which he commands them to obey their teachers on penalty of death, although Moses clearly adds: "what they teach you in accord with the law of the Lord." Thoses villains ignore that. They wantonly employ the poor people's obedience contrary to the law of the Lord and infuse them with this poison, cursing, and blasphemy. In the same way the pope also held us captive with the declaration in Matthew 16 {:18], "You are Peter," etc, inducing us to believe all the lies and deceptions that issued from his devilish mind. He did not teach in accord with the word of God, and therefore he forfeited the right to teach.
He compares the teachings of the rabbis to the "lies and deceptions that issued from a devilish mind", referring to the pope. If he were using the Jews as a kind of code for the Roman Catholic hierarchy, why would he call the pope a liar? These are not the writings of a man in fear of the established church.
I'm sorry. Your theory doesn't wash. Martin Luther was many things, but he wasn't one to mince words. He made public his feelings about the Roman Catholic church and faced death because of it. Here I stand. The majority of the princes around Luther actually approved of the Reformation -- most likely because it promised more local power and authority rather than from religious conviction.
Although most German kings attained imperial coronation, there were often several candidates for the throne. A body of princes, called electors, selected by majority vote both the German king and emperor; the crown, however, was only officially conferred by the pope, who occasionally claimed ultimate authority in the election. Over time, tensions mounted between the emperors and electors who, as one of the three representative groups in the imperial diet (or parliamentary body), kept the power of the monarch in check. The culmination of these tensions came with the Protestant Reformation of the sixteenth century: while the emperors adhered to Roman Catholicism, the electors generally supported the Reformation. It was, in fact, an elector—Frederick III (the Wise) of Saxony—who gave refuge to Martin Luther upon his excommunication. The Holy Roman Empire and the Habsburgs