Your ventilation is totally dependent on overall house ambient humidity. A person living in a very low humidity area will have extreme issues trying to get higher humidity with an all screen enclosure and a person living in really high humidity would want more screen to create more even cage humidity levels. Misting times again are dependent on your environment. A cage in a very high humidity area would be drenched and not dry out enough with extremely long misting sessions. I also would never put a bowl of water in a chameleon enclosure. Not only is this a good way for bacteria to grow but a safety issue for small chams that might get stuck down in the bowl.