Just to jump in and agree with Mike; I would guess the Foundation would prefer not to participate in this as well; you only need to get named in one suit before it just isn't worth it.
Absolutely. After all, they're called "bonds"; it is quite conceivable a judge could be convinced that means the money should be returned to the users in the event of fraud by the entity that purchased the bond if the recipient is well-known.
In this case, though, there might be a business case to be made for an escrow shop or business to do bonded verification. It depends how 'distributed' you want to make things. On balance, I'm not sure why paying miners directly is a bad idea, unless you can work a decentralized scheme where the fidelity bond buyer gets paid back if there are no claims.
In the case of fidelity-bonded banks a reasonable thing to do would be to setup a service that runs a the same sort of trusted hardware cryptographic co-processor with remote attestation the banks themselves would use and have that hardware generate secure fidelity bond deposit addresses. The program running on the hardware would then evaluate any fraud proofs produced by defrauded users, and if the proof was valid refund the user from the deposit address. Equally it could just be a trusted company with some lawyers.
It's not the right solution for every purpose, but the underlying technology has the flexibility to be used this way.