I personally wouldnt carry a fire arm, although one for the home is fine as long as you keep it locked up and out of the way of children.
On the street your best weapon is to be alert and aware of your surrounding's. Make eye contact and "size" up the people you are around. In a sense profile them. As is the case no matter of training can stop a bullet from hitting you, but if you arent there it wont.
You can generally sense those that have criminal intent if you are aware, granted this isnt alway's the case. But yes I agree firearms should be legal but they do need to put some parameters on it. I mean going hunting with an auto matic weapon like a AK-47 is a little over kill. They should have certains restraints on what you can buy at gun show's and shop's. You cant really stop the private dealer's and the thieve's. There is a lot to be said on this subject and I have a little more to say, but alas I am cut short by work
c-ya