Sorry, genuine question, why do you consider this relationship to be "unhealthy"? I mean, they have some issues, some of which are unique to them as a couple, but I didn't get the vibe that it was damaging to either of them. Of course, you and I could just have different standards for what an unhealthy relationship is.
Well, I don't know what you define as unhealthy, but I think that the fact that he or Bianca are not rejected by each other but can't really be together is really damaging for both of them. I mean, cmon, they've been writing letters for 15 years. Do you know how unsatisfying this must be? Plus Varric has to think about Bianca's husband and the opportunities he can give her (because of his money) that he can't.
Because of that I also thought maybe they could give him at least a happy end with him getting over Bianca, recognizing that she is just his old flame, and having a nice romance with the hero of the story. But I guess that's over with, they had got the chance to do it but nope. Life is hard. You have to take it as it is. (I like this ending as well)
Ugh, if they try to make a character similiar to Varric just for fan service I'm out of here.. Dwarf romance ok, but I don't want a substitute to make up for a lost opportunity. They already made my favourite in the game so I'm excited to see the next game but I'm not really all over the romances
Or maybe they somehow will manage it? I hope there will be characters that don't remind you of anyone in the previous games, often it's just too difficult to fit someone in who is entirely different