If op signs a message with an old quoted address stating the detailed loan terms and information, the lender can send the message to a forum administrator to stop
any account recovery attempts.
I still doubt that it is worth lending though, as the collateral needs to worth 10% more than loan value.
Yes, I suppose you're right; the admins should be able to stop any such attempts if needed, by directly resetting the account's password and email. This should allow cryptopaths to still access his account and perform whatever business he needs, even if it won't provide privacy; although, the terms can be rearranged so there would be no need to provide access information to the lender, relying only on the admins to transfer the account in case of default. Still, I imagine they might be somewhat reluctant to get involved like this - have there been any cases where they have intervened in this fashion?
As for the value of the collateral itself, I have no idea; I still remember Hero Member accounts being worth more than 1 BTC, but I guess that has changed a lot since.