Maybe you did the star nut up too tight.
It's possibly all in your head, to be serious. I'm a little sceptical about the normal thoughts on bike steering.
What we do to turn left is give a little pull on the right bar end, pointing the wheel to the right and tipping us to the inside (left) and we spend the rest of the corner "rescuing" ourselves and balancing the centre of gravity in line with our wheels.
Wide bars help us by keeping our arms out, aiding balance, but stem length – I'm not sure about. I do know that riding a friend's Scott Genius with a 100mm and the fork set to 140mm, you need about a minute's notice to make a turn.