Is it possible to finish the Domain of Anguish quests with heroes? What are the tactics/builds?
Yes it is (or was) doable, and actually someone posted a screenshot on Guilgwarsguru forums right within a exzessive discussion on beating Domain of Anguish (DoA) and Fissure of Woe (FoW) alone only with heros. See this guildwarsguru Thread.
But I would advice to not attempt this unless you are REALLY experienced, it requires HUGE amounts of skill, in my opinion.
Someone also posted his complete build on pvxwiki. It says this should be foolproof but I have no personal experience with it.