The failures neither end nor break your game and they certainly don't force you to go back unless you simply must unlock as much content as humanly possible, in which case, tough luck. Play the game in the manner fitting your character and you won't have any problems.
The problem, VD, is that sometimes your view of what was fits your character isn't the same as what a lot of people think, and the result is that several options seem to be missing in the game. "I'm a assassin, so, why I don't have the option of staying on the roof of this house to ambush these two individuals? Why I cannot poison this character using his food? Why I cannot bargain with this one? Why I cannot I steal from this guy here?" So on and so forth. I mean, I understand. You are only one person, and you cannot write all conceivable scenarios and all forms of interactions in the world in your game, this is a problem inherent to games that are deeply scripted.
I guess it's a trade-off, you don't have the absurd interactions like in games that offers more "organic" interaction (like Fallout, where you can go putting dynamite in someone's pocket who is dressed in rags), but on the other hand, the world suddenly feels limited, smaller. Especially because in most RPGs, combat is the "basic mechanic" of the game - all other forms of interaction are built around it, which means that "if all else fails, hit it until it's dead". In AOD, combat isn't considered as the base, it's more like one of the options, you have to consciously make the choice to create a character able to do that. Which, again, makes sense and is part of the game logic, but effectively reduces the number of ways that the player can interact with the world. And since all other forms of interaction are severely scripted, when the game doesn't offer you the (plausible) option that you expected, you feel trapped/stuck.
That's why the game feels like a CYOA most of the time. It's a great CYOA, by the way.