This is something that I wrestle with all the time. Speaking of wrestling, one poster mentioned he has to wrestle his bike in the turns. If you're wrestling the bike, you're doing something wrong. Whenever I find myself getting nervous the accompanying tension that comes with it, I try to tell myself to relax. If I'll do that, lean the bike, shift my position properly, relax a bit, the bike just goes smoothly around the corner.
Also with a passenger, the ride is completely different. I'm too old to try to impress a passenger. Plus my wife has been riding with me for some 12 years. I don't need to impress her any more. I ride much more conservatively with her on it, both for her protection and just because the bike handles so much differently with a passenger. I'll save the risk taking for when it is just me and I'm prepared for it.