It would be very nice to have options. Options don't take away the route of romantic relationships with character which already exists. In case if Halsin and, again, remembering ideas of Cowoline, options may just add something more and slightly correct shortcomings.
Please, guys, understand this: when people expressed their desire to see Halsin as companion and LI and when Larian agreed to do so, there was a limited time period to work on him, to expand his personality and create romance. It had impact, both positive (because people got what they wanted) and not so positive (because, again, dev team had much strict time limits and other reasons).
Can some things be fixed? I think it is possible.
Will these fixes ruin character? Not at all.
Will adding options remove what people like/don't want to change in Halsin's story? No. Choose whatever you prefer.