Remember that people as highly controlled as JWs do not always react logically. By expressing doubts in front of 2 elders and challenging their beliefs you go from spiritually sick to apostate before you can blink.
What may be a ploy is to use family worship night to explore different areas of JW belief that you have issues with. E.g look up quoted sources in magazines and literature to see what the full quote says. Look at JW facts for some ideas of areas to tackle. Present it as a faith strengthening exercise rather than a destruction campaign. Always appear surprised when negative conclusions are drawn. If you challenge JWs directly they cling to the organisation since that is what they are programmed to do.