I broke my nose when I was a kid and the lump left behind has always been bothersome. Would a nose job be a smart choice in fixing such an old problem?

A rhinoplasty would be a nice option to address the deformities caused by a previous nasal trauma. If you have other injuries related to the nasal fracture (a deviated nasal septum, for example), then the procedure may improve your nasal airway as well.