Ubi,
1. Ask him. I reposted in response to the question posed by the O.P.
2. It would have to be per capita as Israel has only eight million citizens. If you include all the weapons in the hands of Hamas it might be more. According to the Wikipedia the US has over forty times as many guns per hundred people (not necessarily civilians) than Israel but America also has much larger armed forces and police departments.
3. I would imagine that it would depend on the state. NYC has one of the toughest gun laws in the world but that has never stopped criminals. Switzerland, on the other hand, has non-restrictive laws and compulsory militia training. However, we have not heard of massacres there. In an case, today anyone can make his own on the Internet so it would make much more sense to concentrate on mental health care and proactive enforcement. The FBI had a number of tips on Cruz and he set off all the warning lights from childhood. Why was nothing done?