All that black soot you mentioned isn't necessarily from burning oil; it is more likely from an excessively rich mixture. Oil will leave an oily feeling residue, whereas a rich mixture will produce more of a dry soot.
Before you get all worried over possibly nothing, I'd suggest a fresh load of oil and then careful monitoring of consumption over the next several thousand miles. DO NOT overfill, as the engine will immediately blow the excess out through the breather system. Also do not constantly add every time the oil level drops slightly. Just monitor and log the level, but don't add until the level reaches the ADD line on the dipstick. There is a simple reason for that btw. Many Harley engines like to run a bit below full, and will quickly blow the excess out the breather system and then stabilize at roughly a pint low. If your bike happens to be one of those, it will become obvious if the oil level drops to midway between FULL and ADD, and then stays there. You won't know that if you constantly top it off.
Jerry