Stating that the heart icon always leads to advancing the romance in a positive way IS useful feedback too. I mean, we did use it in a "fail case" with people like Varric and Aveline, but we could utilize it in different ways. Maybe it's an inappropriate time to flirt, or other things. I do think that the idea that it isn't always ideal is a useful one.
It says to me that we need to make it clearer that the icons depict your intentions with the line, rather than a predictor of the results. This can be done by ensuring that the results the player may expect don't always happen. So we could have icons to suggest that this is a line that attempts to woo the character, but sometimes it doesn't work out in a good way.
Or we could try other stuff for romances altogether? At this point the discussion has gone more philosophical (which is interesting).
I do think it would be interesting to do--in a dialogue mechanic sense...to choose an initial
selection indicating the next lines of the conversation would be in that tone:
For instance:
Potential LI: I was just looking at the stars and thinking...
Player Character:
Friendly: About what?
Clever: about how we'll have to kill all the things all over again tomorrow?
Aggressive: Spend less time pondering the stars and more on guarding your left flank.
Romantic: And here I was looking at you instead and thinking...
Which would lead to a second branch:
Potential LI: And what exactly were you thinking about?
Player Character:
Romantic--friendly: How beautiful/handsome/clever you are...
Romantic--charming: About how that starlight would look on your skin...
Romantic--Aggressive: About how you'd look mowing down darkspawn under the moon.
(I know it's kinda goofy, but it's on the fly.)
Now, depending on the personality of the person you're wooing...maybe one or two of those romantic advances wouldn't work. Doesn't mean the Player Character would get locked out of the romance or need to reset, but it would potentially lead to a third branch which would---if passed---lead to the romance-success branch.
Like if the Player picked right one:
Potential LI: You've got a way with words, dear.
Player Character: *eyebrows of success*
But if you failed:
Potential LI: As charming as that sounds, I'd rather not...
Player Character:
Concession: I tried.
Romantic-try again: Well, what if I said that you're the only one in my heart?
Romantic-try again: So, you wouldn't want me to read poetry about your prowess with the blade/staff?
If the correct romance option is chosen, it'll go up to the previous branch. If not, the conversation might end.