Nothing. HR218 references retired and active police officers carrying a handgun. It has nothing to do with gun permits.
Assuming you mean "gun" permit, yes, the state of Tennessee recognizes gun permits from any state.
It depends on where you are. In the U.S. you can own a gun in any state without a permit, except that the state of Illinois requires an ID to purchase a gun.
California
It depends on where you are. Most U.S. states don't require a permit to own a gun. In order to carry a gun, you need a permit in some states, but each state sets its own laws on how to get a permit, so it depends on where you are.
It depends. A full time or retired officer can carry anywhere in the U.S. under federal law HR218, but there are some restrictions. The officer must follow (most) local laws of whichever state he or she is in.
Some states will allow out-of-state residents to get a concealed carry permit by that state, but not all states do this.
You must have a permit for any gun. If you are caught with an unregistered gun (no permit), you will get a minimum jail sentence of 1-3 years.
It depends on what state. Most states do not have gun registration. A few do, but in most of those states, it's difficult to get a gun permit.
Numerous states recognize the Texas permit.
Ask the State Police.
It depends on where you are. In the U.S. at least, each state sets its own regulations for issuing permit, so it depends on the state in which you apply. If it is a felony charge, in the U.S. you can no longer own or possess a gun, much less get a gun permit, unless you have had your rights restored. If it is a misdemeanor charge, it just depends on the state and whatever that state's rules are.
Generally speaking, yes. In order to get a gun permit in any state, you must meet whatever requirements the specific state sets forth. Check the Texas state website for more information.