Mostly the different lights required will throw off a bit of heat near the top of the enclosure and make different temperature gradients. The UVB, Plant lights and basking bulbs will all generate a bit of heat with a warm spot for basking. With lots of foliage near the top of the enclosure it will allow your chameleon to thermo-regulate, or get out of the heat when needed. You need to be careful measuring the basking site as it can be too hot and cause burns.
As for maintaining humidity, yes a misting routine is needed for this. Most will recommend an automated system that will run on a timer because it is much easier. Also, live plants are great at maintaining higher moisture in enclosures, just make sure they are safe for chameleons (especially veileds that tend to munch on leaves). Some will need to cover a few sides of a full screen enclosure to hold in moisture depending on the humidity levels in the home.