Chuck and Bettina will eventually get together.Both have had a significant chunk of their life torn away: Bettina, discovering that her husband was unfaithful and the implied subsequent divorce; and Chuck, trying to re-discover himself after five years of solitude. Just as her angel-wing package provided a mental anchor for him on the island, ultimately he will seek her out as a mental anchor, a sort of substitute Wilson, as he rebuilds his life. It probably won't work out in the long run, but she seemed secure with herself post-divorce, and could probably help him come to terms with everything that's happened to him.
Chuck wasn't serious about committing suicide.Out of various other methods he had at his disposal and could have tried, he chose hanging. Not only that, but hanging from the top of the island. He could have used any tree to hang himself. He could have slit his wrists with anything sharp. He could have drowned himself. Instead he thinks up a complicated way that requires testing. This guy wasn't serious, when it came down to it - just lost.