I don't think 2 and 3 are particularly strong arguments. While others may have changed their own ratings, it doesn't necessarily mean that the user who left that rating has changed his mind though there really isn't anything to prove otherwise either. If the forum maintains its position of not interfering with trust ratings, I highly doubt anything can be done about that. There are probably tons of ratings like this and would probably result in people wasting loads of time trying to gather all the evidence and making an impartial judgement after.

Your post probably mainly highlights the shortcomings of trust system. Most trust ratings are not correctly used anyways; I have seen too many negatives that don't necessarily point to the fact that "trading with this person is high-risk". I agree that the first point could have some form of review though, it is not difficult to get the signed message from the hacked account and restore it.