What is the ruling on a wife saying to her husband, "Insha'Allah, such and such will happen to my parents if I am lying," and does that affect the validity of the marriage?

The statement that includes supplicating against your father, "if I am a liar," is a reprehensible statement that should not be uttered. However, it has no effect on the validity of the marriage, whether you uttered it before or after marriage, and whether you were truthful or lying. This question indicates the presence of obsessive thoughts (waswasah), and the best cure for waswasah is to ignore it.