You don't need the danish oil and the poly. I've messed with danish oil a lot. Usually, though, I soak the shafts for days at a time and use a particular color of danish to get the shaft color I want. Oil does not penetrate as well when it is rubbed over a previously applied stain, which tends to clog the wood pours. Three coats of Danish oil over a stain may be ok for damp conditions, but I don't think it will hold out rain. Three coats of poly, on the other hand, because it is a surface coating rather than a penetrating coating, will hold out rain, water, etc, unless the finish is somehow compromised--split, chipped, etc.