A payment channel with a hub-and-spoke model as in the OP does not equal Lightning Network or Raiden in their requirements or what they are trying to achieve. It’s an interesting debate of whether a decentralized network is desirable over a verified provider.
Routing was a problem that we decided to avoid by choosing an application that can work with a simple hub-and-spoke model. It could be interesting to see how many applications could fit such a model. As Gavin Andresen states, a centralized Lightning Network (which really isn’t a network) may not be a bad thing.
You in a way see this pattern in Plasma as well, where more emphasis is placed on verifying that the operator (central bank) can’t act out of your interest. As you say a good set of rules and protocol to be sure you can’t be cheated is the way to go.