I have to say that the 'magic blood' combined with the uber-star destroyer Vengeance has me a bit concerned. But like anything else it'll all be in the execution.
I don't know, a ship like the Vengeance makes sense in the post-Vulcan era and after confronting a ship like Nero's (which was only a civilian mining ship). I'm sure Starfleet has its version of Area 51 and is keeping even a few more secrets.
Don't like the name of the ship, though.
To me, the "magic blood" is problematic and one of the lesser things about some of the technology shown in Trek that's ever bothered me.