1) Our last speaker is dead and we haven't found a new one yet. Speakers have a 'gift' that allows them to interpret the Traveler through dreams/visions. TBH we just don't need one right now and I doubt we see a new Speaker unless the story calls for it. 2) I don't think this is mentioned but I really doubt the Cabal would care about outward appearances. Not because 'they ugly' but their entire culture is different from ours. Put simply they value different things. 3) Become a different Guardian's Ghost? Yeah. Its rare but ghost's have changed owners. I recall a story about a warlord who's ghost refused to revive him and went searching for a new guardian and then there's Shin. IDK about becoming Osiris's ghost though. That would be a first.