The general role of official encompases the role of competitor.  The only difference is that an individual indicating they are an official have the additional attributes of an official associated with their user ID.  Any individual logged in can sign up as a competitor for an event, and they will only have access to the public portions of that event unless they are given a role on the Event Panel for that specific event.  So you don't need to change the way you're setting up events or assigning roles for an event.  Also, there are situations where an individual is both a competitor and an official for an event (a competitor and sits on the protest committee for example).  Again, nothing changes except that individual has access to the Event Panel as well as the public pages.