Lots of fascinating ideas here. Thinking of Sarai as having an STD gives me pause—though it does remind me of a recent discovery that leprosy was seen as a marker of sexual degenerates since ancient times. I'm unsure if that's related to the Bible.
But my understanding is that Sarai is divinely protected and no phallic power can perturb her. I don't mean to rock my own hobby horses, but mentioned some points on this theme here in the discussion of Rahab.