I think you got great advise. I am sorry things are working out with your wife the way that they are. Your greatest weapon in court, and you should not shy away from it, is the open ended question of weather or not if a doctor required her son to receive a blood transfusion, she would allow it, or not.
Don't tell them what she would do, make her say it. Some people find it so unbelievable that they don't take it seriously. This should get you all the visitation you want, and even custody if you really felt like it.