Ask all the questions you need to!
There's a lot of conflicting advice as people do things differently - as long as you get good results, stick to it. Most people just use a heat mat mixed with daylight in the room for a day/night cycle. Others use a combination of heat mats and lights, and some just use lights.
I use just heat mats with no problems at all. The main thing is that you're getting the required temperatures on the floor of the tank. If there's no stat on the light and it's overheating the tank, I wouldn't use the bulb at all for the moment.
Hope that answered your question (in a round-about way!)