If the brakes have been reported as needing replacing, the longer you leave it the more chance of destroying rotors, get it done asap what is wrong with the calipers they rarely cause a problem, the smell may be fluid leaking onto the exhaust.

You can drive on the brakes until one of the pads starts grinding on the rotor; then you get to spend a lot more money on parts that you could have saved. If the rotors aren't worn under the legal minimum thickness already, you'll spend less money by having the pads replaced before they start grinding.