Not an eCash FUDster here but i'll still answer

Agree with the first thing. It's without a doubt an improvement on custodial lightning.

For the last part...either it's simply not possible or there is another layer/technology/schema/protocol that can accomplish it or come close (requires unilateral exit)

But whether we can or can't scale Bitcoin is separate from the fact that scaling IOUs is not scaling Bitcoin no matter how useful that can be.