Question #1) When heating to max Temp, 1200 degrees C, for up to the 2 hour time limit and is completed, Con you turn the power switch off and let let kiln cool back down to room temp on its own? Or should you set to temp to room temp and leave the unit running as it cools down, is there a fan running? Question 2) Can you open the door during cooling or should it be closed when cooling? Or what temp can you open the door?