I understand positive feedback & its effect on a profile but How does negative feedback work?
The same.
The last few trusted feedbacks (as per the trust network of the viewer) are given more weight than the old ones (which makes it way more useful than otherwise).
Neutral feedbacks have zero effect.
Are you saying that after time, your trust score will go down, as the reps you received are becoming more and more outdated?
is it possible to turn trust and associated comments off?
If you don't want to see anyone's trust ratings (other than your own) outside of 'Untrusted Feedback' then you can add the line ~DefaultTrust to your trust list.Be warned that this will (obviously) remove all trust ratings, meaning you may end up dealing with known scammers if you don't check well prior.
Let me just add that this ruins the point of the trust system. A better way would be to type in -*insert name here* in the box to make sure their reps make no effect on the trust you see.