Indeed the term "anti-Semitism" was coined to reflect the shift in hatred towards Jews from one rooted in culture and religion to one root in race. The very fact that you acknowledge that pogroms prior to the 19th century were not based on race suggests that if you had just taken the time to actually understand what was being said you could have avoided your confusion.
It's kind of interesting how any such distinctions have been essentially eliminated. Nature is very mysterious.
Your example of the Pale actually makes the point; Converting to Russian Orthodox actually released you from the rules imposed on Jews within the Pale. Conversion wouldn't save you from Nazis.
Russian folk wisdom says "Жид крещёный - что вор прощеный. Веры нет" - "A converted Jew (slur) is like a forgiven thief - no faith/trust".
And in later times, "бить будут не по паспорту, а по морде" - you'll get beaten up on your face, not on (according to) your identification papers, a play on words meaning if you look Jewish, it doesn't matter that your papers say otherwise.
This is not "weird thing", it's a mainstream view that I got from mainstream Jewish authors on the history of Jews. But hey, maybe those are also weird *shrug*
And your extremely condescending attitude is not appreciated.
Hatred of a people based solely on religion while despicable has a different nature from racial hatred.
If you had googled "expulsion of jews from" you would notice there were many times they were allowed to stay if they converted (at least, give the appearance of). The Marrano during the times of the Spanish Inquisition is a notable example.
But if you are a jew in the era of antisemitism, there is nothing you can adopt to not be a jew. In the eyes of racists, you will always be a jew and the object of their hatred.
So, yes, 19th century antisemitism has a markedly specific nature that doesn't compare to the past.