Were ithyphallic amulets significant symbols in death only or were they used generally in fashion/religion/etc.?
It varied throughout Egyptian history. For example, when the Roman Empire made its way into Egypt, it brought with it the idea that phallic imagery could ward off evil, and therefore was used in a household setting.
The figure of Bes, the ancient Egyptian protector of households, similarly was shown with an alarmingly large phallus to ward off demons and those who might hurt the family.