First it would make it extremely easy to scam account buyers who do not think to ask for a signed message and would make any buyer vulnerable to having their account taken back in the event they lose such signed message. It overwhelmingly appears that the OP is almost certainly trying to scam the person that he sold his account to. The OP proved his account ownership by signing a message contained in an other person's post (but not his own) so anyone buying his account would likely not be able to easily find such address to request such signed message.
You're chalking up account buyers as morons that don't know what they're doing. If someone's buying a BCT account, they're likely not a newbie to the community. Even if they did not think to ask for such proof, that can easily be solved with a public service announcement. If the buyer still chooses to go forward with the account purchase without some kind of signed message as a receipt, then it is their risk to take.
I would say many buyers are new to the community/to bitcoin and want to buy their way into features of higher level accounts. This is why you will often see senior and hero accounts asking newbie questions.
Just because you don't have the receipt for something does not mean that what you have in your possession is stolen.
All that it means is that you do not have documentation of the transaction.
You need to remember that the person who is in control of the account at one point somehow controlled the password so the burden should be on the person claiming ownership not on the person who controls the account presently.
And what kind of proof would the OP have to present to satisfy that burden? What would it look like? What form would it take?
I am not sure. Most likely nothing. It has been said before that the majority of the time, the reason an account is hacked is because the owner was being careless (this is not something you addressed) so I don't see any reason why carelessness should be rewarded. Any criteria that is set in stone would be exploitable by potential scammers.
IMO the only time it would be appropriate to reset a password is in the case of
forgotten passwords when the account in question has not been logged into recently and it is apparent that
no one has control of the account.
... if the administrators were to be as liberal with account recoveries as you are suggesting then theymos would be overwhelmed with requests for account recoveries and this would take his time away for more important work.
Of course, that is just your hypothesis. My guess is that with a more clearly well-defined recovery procedure it would allow theymos to restore more accounts back to their legitimate owners. Of course there's no way to know for sure without trying. And why favor account buyers at all? Theymos himself said he doesn't condone the activity anyway so worrying about account buyers getting scammed is a moot point.
The forum does not look highly upon scammers, they only do not moderate scams. There have been a few examples where the mods have outed the alts of scammers after it has been proven they have scammed. The current policy favors the person who is in control of the account. The fact they are in control of the account means that they somehow gained access to the password at one point. If the forum were to be as liberal about giving access back to old owners then it would be enabling scams.
Couple this with email confirmation on changes to vital account detail, like you read from my other post, that will cull out the majority of the account request to start with.
Email confirmation will not work as the forum does not require email confirmation therefore it is not certain that the email the forum has is a real email address and if it is not it would be impossible to change your password in the event it is compromised and people would be able to scam in your name if your password is compromised.