After giving it some thought, the most important thing that we need is the escrow functionality. If that's already been implemented on Layer-1, as Dan suggested, then we can do some amazing stuff on Layer-2. Private messaging is only required for shipping physical products.

Dhive's library shows 4 escrow operations:

• Escrow Transfer
• Escrow Approve
• Escrow Dispute
• Escrow Release

But, I'm not sure if those types of transactions are currently accepted by the blockchain. I will do some tests tomorrow to find out, unless someone else can enlighten us? @inertia @blocktrades @someguy123