You're kinda all over the place with this one, it might be better if you wrote the reaction out in chemical notation, and tried to predict the products. However ...
1). No, the hydrogen doesn't come from the water
2). Well NaOH dissolving in water is exothermic. But if its already dissolved, then maybe slightly cooled, the heat you get from adding aluminum isn't really connected. Now is it?
3). Now that's a good one. Work this angle some more with some textbook evidence.