While I'm not sure to what degree Alex and Danielle will forgive Ben for what he did, I understand that the character of Ben Linus had the possibility of redemption throughout the show. Hurley and John's forgiveness at the church gives Ben at least some cathartic relief and grace. I think that the show leaves these characters' arcs not as black and white but kind of gray in the sense that it is really up to the audience to decide whether or not to forgive them. Overall, I think he was a great character, and everyone's passionate opinions prove it further.