You should expect them to consume 2-3 gallons per day. Water consumption decreases as time progresses. The extent to which you care for your tree will determine it freshness during the Christmas season. Christmas tree safety is very important and its your responsibility. There has never been a case where a Christmas tree auto-ignited.
Most fires originate from faulty wiring in the lights.
Before you string the lights on the tree, test each string. If they are not working properly and can not be readily repaired, discard them and purchase new ones. The risk of a fire is not worth the cost of a string of lights. Always unplug the lights at bed time or when you are going to be out of the house. This new tree stand can actually save marriages by making the setup of the annual Christmas tree so simple and easy that the customary family bickering and fighting is all but eliminated.