If nationwide carry, concealed or open, handgun or long gun, suddenly became legal, I would not carry a long gun. If you are going into combat, carry a long gun. If you are not, carry a handgun.
Soldiers carry a long gun because they are going into combat. However, historically, not all soldiers carried long guns. Pistols were the weapon of choice for soldiers in jobs where they needed their hands free until WWII when the M1 Carbine was designed with those troops in mind (and it was a gun with roughly the same power levels as a stout .357mag).
Police, who are far more likely to walk into an ugly situation than the average person carry handguns. Many (most?) carry shotguns or rifles/carbines in their trunks so they can get them easily when they are expecting to walk into trouble, but usually they are not expecting it so they have handguns.
When you need to be doing other things, a rifle often will just get in the way. Especially in everyday life when the chances of needing it are low.
So, given the OP's stated situation, and these criteria, I'd carry a handgun and I'd carry concealed. Concealment, as a private citizen, gives a little bit of a tactical advantage over having criminals know we are armed (and carrying something valuable that is easily sold). I'd have different CCW options for different concealment/dress/backup needs: 1911 Commander, 1911 Officer, S&W M&P40c, SIG P290RS, small .380 (LCP until traded on something with better sights), and a revolver or two for camping and occasional use at other times. I would probably follow the lead of police and have a long gun in the trunk of my car in case I drove into a larger situation that called for more.
The exception would be something like the LA riots or the Katrina aftermath where regular citizen homeowners, business owners and their employees basically found themselves in a combat zone and armed themselves with rifles and shotguns to protect their livelihoods and property (though, I guess it isn't really an exception if I had a long gun in the car to cover such unexpected situations).