Scales of Fate

Has anyone completed it? Can you tell me if there are any interesting quests in the elven territory in the fourth mission? I just killed the Ent guards of the treasury along the way, and if I click on Utopia, the mission ends. Or is it just about destroying the elves? It's a shame to miss out on potentially interesting content. Or is it the third mission (I think I got them mixed up)? And also: has anyone managed to defeat the army of the mentor in the first mission, where all the stacks of archmages have over 14,000 units each? Is there a quest related to them?