The two fundamentals listed in post one are independent of each other, in the sense that Fredricksen could be right about 1) and wrong about 2) or vice versa. In fact I think she is seriously mistaken about the first (here we go again with reading Paul through Schweitzerian eschatology just when we thought his ghost had been exorcised from the Pauline discussion) and is mostly wrong about the second one (Paul remained within the pre-existing spectrum of early Judaism) It is amazing to see the tired old view of Weiss and Schweitzer recycled yet again by a very diverse group of contemporary scholars— besides Fredricksen, there is Allison and Ehrman for example. But in any case, she is right that there were Christ-following assemblies set up by Paul which were in competition with synagogues in the Empire in some respects.
As becomes apparent early on in the book (see e.g. p. 2) Fredricksen wants to argue that Paul did not take the message about Jesus to Jews, but rather specifically to pagans, almost exclusively. In order to come to this conclusion a good deal of exegetical gymnastics are required, not only in regard to the book of Acts, but also even in regard to the capital Pauline letters specifically Galatians, the Corinthian correspondence, Romans, Philippians, and 1 Thessalonians too.For example, 1 Cor. 7.18 refers to circumcised believers within his Corinthian ekklesia. Fredricksen argues that these could be proselytes who got themselves circumcised before following Jesus. Really? But proselytes who get themselves circumcised and keep the laws of Moses are simply Jews, like those who are Jews by birth. And in any case, only two chapters later Paul in 1 Cor. 9.20 talks about becoming a Jew to the Jew in order to win Jews! Not just proselytes or God-fearers, Jews. Win them to what or whom? He tells us plainly enough—win them to Christ.
It is extraordinary that someone who once was a Pharisee could now say “to those under the Mosaic Law, I became as one under the Mosaic law (though I myself am not under the Law) so that I might win those under the Law. To those outside the Law…..” and so on. This is very clearly talking about Paul’s attempts to win both Jews and pagans to Christ, and no amount of exegetical gymnastics is going to be able to get around that fact. Paul is not talking about previously before his conversion being a missionary to Jews, trying to get them into Pharisaism either. As 1 Cor. 9.19 makes all too clear, he is talking about having currently ‘made myself a slave to all, so that I might (now) win more of them.’ (9.19).