A few questions from an ignorant European.

Greetings r/CCW,I've been living in Europe my whole life where gun culture doesn't exist. While I support owning weapons for Self-Defense, I'd like to ask a few questions.1: Why can't you practice Tactical Reloads and Drawing at some shooting ranges?2: Why is drawing a weapon and not firing it with the intent of defusing a situation frowned upon?3: Why do you often discuss ammunition caliber? I mean 9mm, .45, 10mm should have the same lethal effect. Why would you want to pick a specific one?4: What's the deal with shooting before you see a direct threat? E.G: Two guys are in your house, they do not seem to be carrying weapons but one of them reaches into his pocket. I (personally) would shoot him if he doesn't comply with my requests and reaches into his pocket as I wouldn't want to risk a personal injury or my family's.Thank you very much for your answers in advance.Edit: Regarding point 2. I specifically mean drawing a firearm when you have the intent of using it. Not just randomly drawing it for any tiny disagreement. It just so happens that whoever is at the other end, comes to his senses.Regarding point 4: I'm wondering if you're justified discharging your weapon in states where the "Castle Law" doesn't exist. I've seen discussions where people do not agree with shooting somebody in your home that does not posses a weapon, or is an established threat to you or your family's safety.Again, thank you for your replies. via /r/CCW https://ift.tt/2NIfmGy