While I'd prefer Trek actors do the readings, I'd happily accept non Trek readers.
I definitely prefer unabridged, to the point where I might not bother getting new abridged audiobooks.
I love Big Finish's audios - Doctor Who and Dark Shadows especially, but I get just about everything they put out, their quality is very very good.
I have gotten a lot of Graphic Audio books too.
I think Audible is an excellent potential to produce the audio books themselves.