They should not be.
Provided you follow all the appropriate laws, yes.
Pretty much. Stricter gun control and vehicle laws, though.
Many lives were lost, gun laws became stricter.
In the entire U.S. there are an estimated 20,000 or more gun laws.
You are asking for an opinion. My opinion? The US already HAS several THOUSAND gun laws on the books. The problem is that people that will not obey laws that prohibit murder, robbery, and assault also do not obey gun laws. If you do some research in the FBI crime statistics for different places, you may be surprised. Some of the places with VERY strict gun laws also have VERY high crime rates.
Legally, most everywhere you can keep a gun in your car and in your place of business. Check local laws to be sure. In practical terms, keeping a gun in the car is a bad idea because it can get stolen very easily.
A gun is a bit of machinery. It is neither good nor bad. It can be USED to do both good and bad things by people, but it is the PEOPLE that are good or bad- not the gun.
No matter WHERE you use a gun, there are laws that govern what you can and cannot do. If you do not know those laws, please do not own a gun.
Your question is an incorrect statement. Why do you think states must not enforce gun laws? They do.
That is too broad of a question to answer as asked. Is there some specific information you want about gun laws?
If you have the correct licenses, almost anywhere. Although in america, gun laws are fairly relaxed, so that's where you would start.
Literally, tens if not hundreds of thousands of laws. My copy of US state gun laws is about 2 inches thick. It is estimated that there are more than 20,000 gun laws in the US- and you are asking about "around the world".