As yet Warwicks past is "dark and mysterious", so Soraka being involved in his life is still a possibility. I would like for him to have been the cunning and cruel manhunter – not just some mere cutthroat – who used his wits to deceive a celestial; and on the same page for Soraka to still be literally too good for this world. Whether she fell in love with the man Warwick pretended to be or just felt incredible pity for him, in the end her kindness proved to be her downfall, just like Warwicks cruelty for him.
Maybe Sorakas curse was more metaphorical and she damned him to be seen by the people like the monster he tried to hide. Not as literal monster, but as a bad person; potentially enough for Singed to (turn on his old friend and disciple and) be inspired to turn Warwick into a real beast.
I always liked the duality Warwick and Soraka represented together. Both pure kindness and cunning cruelty turned out to be their respective downfall and both Warwick and Soraka ended up transformed as a result of their mistake.
As always, we can't say for sure what the lore will have in store for us, so I won't judge Warwicks story until then. I just hope it doesn't turn out hollow; with or without Soraka.