On the idea of a time war,
I rather liked the idea which was illustrated in the story
line leading up to The Wedding of River Song. You'll recall
how the doctor stopped time to prevent a catastrophy, eg his
own death. He effectively Stopped time until he'd worked out
how to cheat time. Perception being everything.
Were it to occur, a time war might be a chaotic event, plop!
or series of events. Some alluding to human history, it
triumphs, as well as its disasters. Un-inventions of all those
peoples and ideas through which we've evolve. Un-inventions
leading to sterility, and a form of wasteful domesticity.
{what if the titanic hadn't sunk, or the hindenburg hadn't
gone up in smoke. "oh the humanity" [these and more passing
references to serve as lessons on a forgotten history] }
The price of that Time war, we already know of as the
uninvention of gallifrey, wiped from time. Perhaps this
occured after one key moment failed to occur, as it should
have. Perhaps the doctor had a hand in that choice. Gallifrey
together with his immortal enemies, or the human race?
What would be the point of time lords without their sole
charge.
CGI would have a field day illustrating the coming and going
of timelines. The visual evidence of fashions and taste, the
appearance of developments and underdevelopments. Technologies
coming and going in an trice. Peoples and cultures turned on
their head, again serving to illustrate what we now take for
granted. All this at the wave of a time lord's wand.
The tardis would feature as the only device we know to
manipulate time, or maybe the Tardis had a mother, also
lost in the wars.
Now what does the doctor do prevent this? What could you have
done, what can you still do to prevent it. Tagline to another
time fantasy..