Be happy you have a gas stove. Turning off the gas will quickly stop the boil over. On an electric the coil will stay hot and you get a mess. The water bottle is a great idea too.
Normally I would say with the first try on a kit to follow the instructions to a T. Your ideas are well researched and proven so in this case, brew on. What I don't suggest is changing the ingredients on the first try. If you do you won't know if the recipe is not so good or your changes were.
Sounds like you are ready to brew! Have fun and don't worry. It will come out beer, good beer.