You can dremel (sp?) the teeth off the outer ring. I ran a 7 speed with one ring in the front and found the chainring wore out really fast and the chain begin to slip. As a broke student I flipped it and used a hammer to flatten the teeth back. As for brakes, I have both on my geared and fixed bike. I like the idea of having the back brake in an emergency situation.
__________________
When sadness fills my days
It's time to turn away
And then tomorrow's dreams
Become reality to me