This sounds like the first thoughts into the (dlux_open_token)[https://github.com/dluxio/dlux_open_token] architecture. If you want to help us generalize the token architecture further as we turn it into "honeycomb" we'd welcome your support.
There are several things you're likely to run into with your current roadmap. One is the databases you mention don't have transnational handlers so you'll likely need to make some custom handlers to ensure order. You might find a p2p layer is overly complicated and unnecessary unless you want to allow transactions that aren't signed/ordered on hive. You'll need to build an exchange because there is no substitute 0x or swap protocols on Hive.
As far as the why and how will this benefit Hive: Having smart contracts in Hive/HBD denominations is a major boon to our ecosystem. With our decentralized wallet those things are possible, and well as a DEX.