I'm not aware that it is against the rules to test people's trustworthiness. But I don't think I've ever seen a list of rules, so maybe it is. That would seem like a strange rule though. It seems to me that it is better to give ratings based on evidence than on heresay, which is what I did.
There are no rules regarding when you can and cannot give trust (neither positive nor negative), only generally community accepted guidelines.
In the past reputation loans (which there has not been an explanation as to why the loan was given other then so tspacepilot can prove he will repay) has been something the community does not appreciate and others have received negative trust for both giving and receiving such reputation loans. The reason for this is that there is no reason for the trade other then for the trust rating. This causes their trust rating to reflect that they have had more of a history of trading honestly then is true because they would have one trust rating and zero honest trades (and no receiving money and then instantly giving it back is not an actual trade).
To respond to your implication that my rating is based on hearsay, as I mentioned several times in the past, my rating is based solely on what tspacepilot said, and what my understanding of the rules of coinchat are/were. However I really did not even need to rely on the former because tspacepilot admitted to receiving money that he knew (at the very least after the fact) did not belong to him:
https://bitcointalk.org/index.php?topic=303613.msg3252748#msg3252748 (he locked/censored the thread, so I cannot use the "quote" feature of the forum)
I cashed out more than he wanted from his site which gives out free bitcoins for chatting.
I don't see how it could be any more clear that he received money that he should not have......would a signed confession be enough? How about an admission in open court?