I can't see the Orlesian civil war ending without Val'Royeaux being included someone. If we kill Gaspard and Celene remains empress, for example, I can't see her continuing to sit around the Winter palace, rather than returning to the capital.
Unless they just leave the game altogether at that point, and the coronation/ reclaim of power happens off-screen.
That'd feel kinda anti-climatic, though.
Something I am interested in knowing is which factions will be nemesises with each other. I mean like how the dalish in DA:O were enemies with the werewolves, Bhelen with Harrowmont etc. We know that there'll be mages and templars, but I'm unsure if the templars will be an actual faction that can join you, or if they've been swallowed by the red templars completely. Similar with the orlesian civil war, where I thought it'd only be between Gaspard and Celene, but some article stated that if you help the orlesians you'll lose reputation with the dalish (or something along those lines). Perhaps I've just misunderstood how that works, but the way I interpreted it was that if we help either Celene or Gaspard we won't be able to ally with the dalish (or at least have a harder time doing so). Could be totally wrong, though.