I was a nervous about overlap when I started riding fixed too. The only times it will be a problem are when you are making tight low speed turns, and possibly when you're learning to track stand (ex. trying to stand right foot forward and turning your wheel to the left to catch your balance). In both cases IF the overlap actually causes you to fall it will be at low-no speed and you shouldn't get hurt. You can also often get around the low speed cornering issue by leaning your bike more than usual while keeping your body fairly upright. At high speed you're never going to need to turn your wheel that much so the overlap isn't an issue.