Hello @storagetur,
Welcome to the forum!
You described several use cases and @lyoth is correct - you will get 10% bonus if you would pay with STORJ tokens (at least for now, while we adding tokens manually).
I would add another use case - Storage Node Operator can be a customer too, and since they already have STORJ tokens on their wallet, it can be simpler to pay with STORJ tokens for the Storj DCS service. In the edge case they may specify the generated address as their wallet and skip the fee problem, if their goal to exchange their shared space and bandwidth to usage of Storj DCS for their own needs (Storj DCS will be more reliable than a one disk for backups and personal data). Please note, zkSync is not supported yet, so in such case SNO need to opt-out of zkSync, and withdrawals would not be possible.