I like the concept sketch, though I'll admit I've never really liked the whole "timeship" idea. While I can respect the notion of a future Federation/Starfleet seeking to prevent major shifts in history, I think giving them this level of technology is just silly. There's too much temptation to misuse it, and you can't say for certain that any particular action or future outcome is necessarily wrong.
As humans and the Federation evolved over the ages, and as the Earth became unstable due to unstoppable geological circumstances, they were forced to move.
Across the Universe they travelled. To the Gallifrey System. There they settled on their new Home Gallifrey, and in the arrogance born from their ability to manipulate space and time, they created a new caste of people. They called themselves Time Lords.
From that point on, a whole new series of really cool and fun adventures began with an outcast Time Lord known only as The Doctor.
So it all makes perfect sense now.
Okay, okay- on topic. I can't really say much about the ship in this post. We need more images. So get to work, BorgDude!... I mean, BorgMan.