I had a similar noise from the front wheels of my '85, which got worse when I turned the steering wheel. Turned out one of the metal dust shields was rubbing against the brake rotor. It was just a simple matter of bending it well away from the rotor and that fixed it! Some people cut them off entirely to improve brake cooling.

Regarding the exhaust noises, they all do it after awhile, as the the heatshields come loose over time and start to vibrate against other parts. Sounds like it's time to upgrade!