Or we can ban the people with negative rating from posting on lending thread as the people with negative trust are potential scammer
These suggestions disregard that negative trust can be given for any reason. E.g. i personally do not trade with fascists, so they get negative trust from me as a personal public reminder. Maybe for you that is no reason to cancel a deal.
Others might give negative trust for other reasons. You allways have to check the trust yourself and can not rely on the number beeing negative or positive.
Also: this should be in meta imho. thx