Re: Timeline of Nolan's trilogy.
I dont think it matters. If you think TDK takes place 1 year after the events of Begins, then that's fine. If you follow the manual and TDK is 3-5 years after Begins...that's fine too. It's not a crime if you choose to believe Batman operated for a lot longer and fought other mobsters and hitmen like Penguin, Black Mask or Deadshot in that timeframe.
They're not really specific enough in the movies so you can fill in some blanks if you please. But treating the 3 films like that's the entire story of Batmans journeys? Ya why not.
Warner Brothers. Focus on a Superman sequel. Reboot Batman, Arkham style. Give fans an origin film for Wonder Woman. And finally create a World's Finest. Do NOT rush into Justice League.