Even though I do it I wouldn't advise you to put a freewheel on a stepped hub because it wasn't designed for that purpose so naturally catastrophic failure may result. Also don't ever run in walking shoes whether trying to catch a bus or rushing to get somewhere... they weren't designed for running so you may blow out a knee or ankle. I sure hope you don't ride with anything but cycling shoes either... any other shoes won't work reliably because they weren't designed for cycling. Better safe than sorry.