When they bring up the fact you had a gun everywhere you could conceal one and three knives you'll be picking up the kids and heading to the local shelter as the turds family moves into your house.
Unlikely.
http://www.azleg.gov/FormatDocument.asp?inDoc=/ars/13/00413.htm&Title=13&DocType=ARS
13-413. No civil liability for justified conduct
No person in this state shall be subject to civil liability for engaging in conduct otherwise justified pursuant to the provisions of this chapter.
If it's NOT ruled justified a person might have a lot worse things to worry about.
Usually one, many times two, depending on what I have available. I carry a spare tire in case one of four breaks, and a fire extinguisher in case of a fire, not to mention a whole host of other safety gear, just in case, many times related to mechanical failure, and these are highly engineered and very expensive automobiles. I have NOT yet figured out how to cheaply carry a spare car, however....
Right now I am proving naysayers wrong by concealing a duty sized CZ SP-01 Phantom with the normal capacity 18 round mags, just to show it can be done. Not the easiest thing to conceal, but it can be done.
Good backup for my CZ P-01.
Evan Marshall of Stopping Power fame, with 23 years on the street in one of the roughest towns around, Detroit, carries three handguns daily, in a neighborhood where he says, "someone stealing a bicycle is a crime wave." He's been there, done that, battle scars to prove it. I'll listen to a voice of experiance, and carry a second gun as often as I can.