The general challenges with designing WoT systems as I understand them are:
1) To make hard to create clones
2) To make hard to hurt reputation for no reason
3) To rely as little as possible on anyone else but yourself
cyberagorist shows that general purpose WoT's are doomed and proposes for a set (network?) of single purpose WoT's. Also proposes for a "with arbiter"-style network which IMO we already have today in real life with threats from government, judges as arbiters and blacklisting as having a record of serving a prison.
But this proposal misses the point IMHO as WoT is exactly that - web. Decentralization and disintermediation from judges. Who are basically are no longer your peers and you get a classed society with all the consequences. The proposal for have a way to trust arbiter is something like overlaying another WoT on top of it.
I believe WoT must be way simpler and exclusively peer-to-peer.
The subset of WoT's related to economy might be like this:
The first problem of creating clones could be mitigated my "weighing" each identity by the amount of provable assets (bitcoins, glbse stocks, etc). After some thinking I concluded that, strangely, you would not want to count identity's debts. In that case the important thing there would be to make sure it is impossible to transfer debt from identity to identity. But that is impossible because in a desired environment it should be possible to transfer assets from identity to identity and leaving whatever debts.
Another thing to weigh identity is its age and its age-assets history. New and suddenly rich identities signal a clone. As well as old but then suddenly becoming rich. In fact the trustworthy identity's age-assets history graph can be expected to be some sort of a curve and weighed as closeness to that curve.
This approach makes "growing" clones by imitating successful financial activity between them slow and hopefully pointless.
To make hard to hurt reputation for no reason there clearly must be some cost to do so. In case of bitcoin economy - see first word

You should pay to change someone's reputation.
As for self-reliance I believe this is already solved with existing technologies like Free Software, Open Hardware and DHT communication and storage networks.