Yes and no. Yes, they do have legislation for concealed carry. No, they're not going to approve you for a permit unless you're especially well connected.
Illinois is the only state without concealed carry legislation. Several other states have legislation, but don't issue concealed carry permits.
I assume you mean concealed. Not without a permit.
No, having a concealed carry permit in one state does not necessarily give you concealed carry privileges in every other state. Most states have reciprocity agreements with some (but not all) other states.
Washington D.C. has always been the most strict about handguns, followed by California. As far as concealed carry goes, Wisconsin, Illinois and D.C. do not permit concealed carry, period. However, states such as California, New York, New Jersey, and Massachusetts are technically "may issue" states, it's practically impossible for an average citizen to obtain a concealed carry permit in these states.
You didn't really ask a question, but I'll give you some basic information on concealed carry. Each state sets its own rules and laws regarding concealed carry, so each state is different in the process to obtain a concealed carry permit, or weapons permit, or handgun permit.
Yes, if you have a Texas concealed handgun carry permit, or a permit from any state with which Texas recognizes reciprocity, you can carry a concealed hangun in Texas.
There is no gun registration in Virginia. As for concealed carry, you must possess either a Virginia concealed carry permit, or a concealed carry permit from a state whose permit is valid in Virginia.
This is a question which needs to be directed to the TSA. As you are traveling to California, if you are not a California resident, you'd be best advised also to contact the California Department of Justice regarding your abilities to carry a concealed firearm there. They may not recognized your position as an out-of-state police officer as justification to carry a concealed firearm, or may require you to obtain a non-resident permit to carry a concealed firearm in the state. Before you depart, you can contact the local TSA representative either by going to the airport in person, or by phone. I would advise you to do this well in advance of your flight, as it is not likely to be a particular fast process.
No. As of 2010, Arizona allows anyone who can legally own a handgun to carry it, openly or concealed, without a permit. Before then, you could carry openly without a permit, but not concealed.
No, Washington DC does not allow concealed handgun carry, nor do they recognize permits from any other state.
With the proper permit and not concealed. actually, the concealed part depends on where you are. In the U.S. each state sets its own laws for permit issue. Some states allow concealed carry, some state allow open carry, some states allow either.
There is no federal law specifically addressing the issuance of concealed-carry permits, so each state's government determines the laws around gun permits and permissions: the details. The federal government will not allow a state to prohibit the right to carry a gun, so Illinois had to allow its residents to carry a concealed weapon as of January 2014.