Failing in various ways can influence other things apart from the romance itself. But then, we're not talking just about the romance plot and the point is moot. The romance plot itself can have only two outcomes: success or failure. If it succeeds in more than one way and/or fails in more than one way, then these variations necessarily influence other things/events in the game world, and, as I was saying, we're not talking just about romances anymore, but about the wider C&C. In that case, yes, some of the romance failure states can give you advantages in other areas.
Not
just influence other things, the romance can influence the relationship to the NPC in general, and choices could change the nature of it going down the path of inevitable separation. Circumstances outside the relationship can further influence it, creating separate problems. Problems in and of themselves probably do not equate to 'romance path continues or ends', which is too simplistic, though some of them may, whether they're immediately obvious or not. But choices alter the ongoing impression of the NPC, which also should not always be obvious with such shit as numbers flashing across the screen and queues from behavior. Kept entirely in the background, and a more sophisticated gradient than an ascending or descending number, anyway, preferably. Sometimes it 'ends' without even seeing why. Oh, that's frustrating? Too fuckin bad, that's life. Get over it. Play a *character* and see what happens, don't try and game it. Guess your way through.
Unseen variables can create more or less random scenarios to further challenge the Path. Including things simply happening in the greater plot. The path being inevitably doomed, its like a slow attrition. Depending on choices, the circumstances on how it happens can be entirely different, and the aftereffects in different gradients of consequence. In many cases, the consequences coming down from the choices are beneficial, and even the end can have a saving grace, despite the fact the 'romance' part is done, killed. The key to dismissing the win/loss formula is a battery of effects, some good, some bad, some in-between, some hard to even say. In the relationship, in the world, in the NPC, in the PC, etc. The possibilities seem endless to me. Just depends on the designers and how much time is allocated to it.
As a random thought, one interesting conclusion might be with a telepath character, where the PC and they form a permanent mental link/communion (by whatever means, maybe even by accident or outside influence). Perhaps this act alone concludes in their minds that the bond is not what they thought it was. Perhaps they learn this in the exploration. Perhaps they cannot handle it, and after an arduous, scarring ordeal, they find a way to break it, and their once seemingly-promising relationship is entirely shattered on a psychic level, with many different aftereffects of it's own.
