You should not use a red bulb as a basking bulb. These are typically sold for keeping a reptile cage warm at night (and can allow keepers to view the activities of nocturnal reptiles), but they should not be used for chameleons because 1) many chameleon species benefit from a drop in temperature at night. 2) chameleons are able to sense light even when their eyes are closed because of a photoreceptor on the top of their head. They require total darkness in order to sleep well. 3) I've been told white light is important in stimulating normal chameleon activity and behaviors. Red will not do this.
Most people use a regular incandescent bulb for basking. You can try different wattages to get the correct temp.
Yes, many people place lighting directly on the top of the screen cage. Just make sure the basking branch is an appropriate distance from the light. You may need to move lights off the top if you have a baby that likes to hang directly under it as they can get burned.