tl;dr: Never run events alone - always have a co-organizer.
One of the easiest (and most fun!) ways to make sure you're replaceable is to never run a meetup alone. If you organize a meetup, find a co-organizer and split the responsibilities with them. This helps avoid burnout, plus it's a great way to strengthen your friendship.
My friend Will and I organized the Austin Effective Altruism meetup together for a year. When one of us got busy with life, the other was able to keep things going. And when I moved to Berkeley, the meetup just automatically kept going - I didn't even need to appoint a successor, there already was one.
I follow a similar model running Authentic Relating Games at REACH. I try to always have a co-facilitator - it's way more fun, takes some of the pressure off, and it's an easy way to train potential replacements for myself.
This is great, I will probably steal it for my apartment, except with empiricism as a scale instead of an eye.
Good work on the guide! Are you planning on combining this with the readme or linking to it from there? There's a bit of redundancy between the two.