If you are using a heat pad you shouldn't need the lamps. You need at least a dimmer for the heat pad. They get really hot and can burn your snakes.
You need to move one of the snakes out. The only time snakes should be kept together is when they are breeding and even then it's only for a few days a week.
You should still try to move them away from your stove as well it will cause heat spikes when you cook.
Did you quarantine your new snake before you put it in with the one you already had?