If you're concerned about "consign[ing] my personal data, beliefs, preferences, relationships, work history, daily plans, and private messages to a massive advertising corporation" but don't want to miss out on seminal life events, why not just maintain a Facebook account without ever posting to it?
As long as you remain friends with people you need to keep in touch with, but never post anything or fill out your personal details, you will not be giving up any privacy or missing out.