I would suggest that you try to mend your relationship before you start questioning jw doctrine. You need to try to get access to his genuine personality, not his cult personality. Fix your relationship now, and when he inevitably tries to recruit you, go slow and try to make your interest seem genuine and just ask lots of questions. Don't make it obvious that you've done a lot of research to find scriptures that go contrary to jw doctrine - just adj questions when the inconsistencies present themselves. For example, they love to rag on the Pharisees and their many rules for everyday minutiae, but they themselves make lots of unscriptural rules for everyday things. Facial hair being forbidden is a good example.
Be prepared for a slow process - if you rush it, you'll do more harm than good.