^ I'd avoid using duster cans, especially on contacts. Old toothbrushes work best. Or grab some cheap paint brushes and trim the bristles down, this works really well for dusting just about anything. Cheap brushes are about a buck a piece, and you can get them in varying width sizes. Used toothbrushes are free. If you're replacing your toothbrush every 6 or however many months you're suppose to, you can accumulate a ton of them on your work bench.
For broken traces, I always just used jumper wires. I find it's easier and faster than anything else. And just as good, repair-wise.