Do hermit need full spectrum lighting?

They do not require a heat lamp, though it sometimes may be the best choice. If you get a heat mat, it is best to go on the bottom of the tank. It warms the sand/dirt/water or habitat that they are in. Heat rocks are also good. You can get those almost everywhere in pet shops. The humidity in your tank sounds about just right. The temperature should be 75-80F. But, back to the heat rocks, It provides the correct accurate temps for the h and it serves as a rock (obviously). You may use the bulb, but when it gets too hot, take it away and the temperatures should be warmer when they were and they shouldn't go down with all the equipment you are using in the tank. I wish you the best of luck! Hope this helps!!