You've started out with a great setup.Batteries are not a thing you should cheap out on,only get the best.Browse around the forum and you should get an answer for everything you asked about.Mech mods,VV mods etc.The amount of vapor depends on how much VG(Vegetable Glycerin) is in your juice and the PG(Propylene Glycol) is where your flavoring comes from. Most places carry a 50/50 blend,but there are a lot of places like some vendors on the forum who can customize the juice to your specific preference. I hope this helps you get moving in the right direction.Welcome to Vapor Talk