I hope no one minds me stopping in to say this so late, but I just finished reading this myself. I really don't have much to say but it's not just a good Star Trek novel but a good novel period. You could change the names and places and it'd work just as well as an independent piece of science-fiction. The fact it works with a "no show presence" star is another major part of its appeal.
So, bravo Una, you did an awesome job.