It's a lovely idea. Fundamentally sound. Feels very Quaker in outlook. That's not a criticism.
I'm not sure it is hardened against bad actors though. I'm sure you've thought of this. Ultimately it needs centralised adjudication. Who is to say if someone did or did not break an agreement, or whether that breakage was deliberate or accidental and whether being shut out for breaking said agreement has implications of a social and financial nature?
Mob rule, designation of "outsiders" and sin eaters feature in almost every social construct at some stage in development. I'm not sure you can avoid that through good intentions.
Perhaps that sort of thing needs to develop naturally, or organically.