That is a bad idea, basicly you are carrying a gun that is not ready to use. The average gun fight isabout 3 seconds long according to FBI statistics, and that's from initial contact not from when the bullets start flying, given that, and the fact that you will probably be caught by surprise (If your situational awareness is good you can generaly avoid the fight, that you didn't suggests you were caught by surprise.), and the fact that action beats reaction, and your actual time to draw, and fire is closer to 1-2 seconds, you simply do not have time to fiddle with the hammer. If your gun is not ready to go when the fight begins it will likely not be a factor in the fight as you will not employ it.
Additionaly cocking the hammer is a relatively fine motor skill that can be fouled under stress, assuming you remember to do it. It also requires you to break your firing grip to do, unlike the safety, you would have to rotate the gun in your hand bringing it out of position in order to put your thumb over the hammer (a proper 2 handed firing grip on a pistol has both thumbs on the support side facing forward one on top of the other, as opposed to the crossed thumbs of a revolver grip).
The 1911 was designed to be carried with the hammer back.
As far as carrying in condition 0, or 1, you should never rely on a mechanicle safety, if you are practicing proper safety your finger will be off the trigger thus you do not need the safety, in fact the 1911 was originally designed without a manual safety as the M1910 the safety was only added because the military insisted on it (they were transitioning from revolvers, and the officer core who were used to the heavy trigger pull of a revolver didn't trust the lighter trigger of semi-autos) the new model was called the M1911. Most modern pistols don't even have safeties, even single actions like the Springfield XD. When I carry a pistol with a safety I carry it with the safety off.
NO it was not, this has been debunked over and over, and actually I believe in this very thread. Several models were submitted to the US army without a thumb safety including the 1910. They were rejected until Colt was forced to add the thumb safety, this is undisputed history. I cannot understand how anyone who makes claims of nomenclature of 1911's would not be aware. Soldiers have been cocking hammers on guns for over 200 years without difficulty. Your contentions are bovine scatology.