What is known about the Apostle Paul's family? Did Paul's wife travel with him and then he became a widower? Does Pharisee of Pharisees mean that his family goes back several generations, father, grandfather, etc. of Pharisees? What does Roman by birthright mean?
Any speculation about Paul's wife (or lack thereof) is just that, speculation.  Unless there is some authoritative extra Biblical source, we know only that he is, at the time of his writing of I Corinthians, unmarried and the inference is that he has never been married (But each man has his own gift from God. I Cor. 7:7).  As for 'Pharisee of the Pharisees', it is emphasizing that he is/was the "best of the best" as can be seen in the context.  Paul did not brag but did not exhibit false modesty either.
Finally, pertaining to his Roman citizenship, one could be born a citizen, purchase his citizenship or earn his citizenship through some service to Rome.  Paul was born a citizen because his father was a citizen.  The speculation is that his father performed some service for Rome but that is only speculation.