I'm hesitant to throw this in, because it can be highly flammable with the wrong people, but religious hatred cut both ways in those early days. NOT that Christian anti-semitism is thereby justified. But it is also true that very early on the Jewish Christians were villified and cursed by the rabbinic establishment.
The adoption of pagan practices into the church happened over centuries of time, as the Jewish component of the church shriveled in comparison to the huge influx of Gentiles. At the Council of Nicea, the Christian Jews were finally squeezed out, forbidden to celebrate Passover.
It is well worth noting, that at the first Jerusalem Council (sometime after Paul's ministry was well underway) the main controversey was over the issue of whether it was possible for a GENTILE to be a Christian, or whether only Jews could be Christians.
Agreed. The rabbis came up with the Birkat haMinim around 90 AD, and of course the Apostle Paul was always being chased out of town or a synagogue by some angry crowd.