Here's the short answer to all these questions.
0.62 was leaked before it's planned public release, again, which I'm not thrilled about. Had whoever hacked it or leaked it early included the faq sheet, it would have added more info explaining the length of content available. Early release was supposed to be a patreon perk and was also supposed to part of my play-testing phase so there's likely to be some hiccups and bugs I didn't catch on my play-throughs.
You can't complete the Elixir of Life Quest. It's just not done yet. The Sin of Man portion didn't make this release.
A bunch of the game is not done. I'm working on it as much as I can get away with, so you'll just have to bear with me.