Sometimes users realize that their initiatives are actually way bigger than what their company deems acceptable size for initiatives. It should be very easy to convert an initiative to a goal. If that initiative includes Epics (Master features), then the user should be asked if they want to shift the initiative to a goal for all of those records. Furthermore, the user should be prompted to put a new initiative in its place, or they can leave that for later.
all of this should work vice versa as well. There are times when goals show up to be too small, simply because the initiatives below them are also too small to be initiatives. In this instance, a user should be able to convert a goal to an initiative. All of the initiatives currently linked to that goal can either stay initiatives or be converted down to Epics (master features.) If you have to force the user to clear out the initiative of other epics first that makes sense. Some of those may become stories (features) others may stay epics.)