You have to travel through frost back mountains to get their
You leave the same way you entered, there shouldn't be anything plot-related stopping you from doing it.
He's at the Aeducan Thaig, the location of which you get from Lady Helmi in Orzammar. If you're at the Thaig, it is fairly linear and it's impossible to miss him.
Leliana is a rogue in dragon age origins. She is a bard, (type of rogue,) and you can learn from her. She loves embroidery and pets, in orzammar you can buy her a nug. Her personal quest is about getting revenge on her old master, Marjolaine.
The 'army' is gathered as you visit the areas that the plot opens up for you at that point. You will need to go to the Circle Tower, Orzammar, the Dalish forests and also complete the quest to heal the Arl. Depending on how you complete each area, you will gain allies to join your army, and the quest is completed when you've done it for those four areas.
Not including Drakes or Dragonlings, there are the following Dragon encounters. 1 - Dragon in the Elven Ruins (Werewolf Lair) 2 - Dragon in Orzammar's Throne Room (Caged in Stone) 3 - Dragon Thralls (Outside Fort Drakon) 4 - High Dragon (Mountain Top outside the Urn shrine) 5 - Flemeth the Shapeshifter 6 - The Archdemon