This is just stupid. If MC ran all the errands for the guild, he’d know the prominent shops. But that’s not the most glaring thing.
If MC has only the power to grant XP, and your guild gets weaker after he is gone, it’s obvious he took back the xp. Why be a dick to him? It’s obvious you would t want him too strong as you’d lose control. But to abuse him and boot him is just dumb. He’s your power boost. And a kid. I’d have treated him like a son, not a slave.