The nuclear option for us is banning someone from the marketplace where they'd have to use another service. We'd try to avoid this, of course, and being accused of "censorship"

I think we need something at LN code level, that will "lock" that channel in some way, for a certain time, defined by both peers.
You as mediator for those channels, you can't do much, just playing with that reputation score.

DarthCoin

This is true and an area for further development. We can't see who closed the channel without someone telling us. But, we can report the history of early closures and users can come to their own conclusions. We can also allow users to report their consent with an early closure.

jestopher

bitcoin

Magma: A New Channel Marketplace on Lightning

I like it!
How would you impose that limit of how many days/months the channel must stay open?
What happen if after 2 days the channel get force closed or simple the peer that open it just close it?
The reputation system can't help in any way to prevent a force closed channel.