I would also oppose a flag on Hhampuz based on the evidence I have seen so far. He has a right to make poorly formed accusations. You don't have a right to punish him for it.
The yellow box is specifically designed to warn newbies and guests. Based on the comment below I feel more justified to use it than e.g. old-school negative trust, which had a red warning visible to everyone. I believe newbies and guests should be made aware of Quickseller's bad business habits and that is not a punishment but rather information to help them make informed choices.
There are three very separate scopes for trust which need to be kept separate. Newbie-warning flags are only for warning newbies, not for warning experienced members who should know better, or for harming the target. The "#" symbol is supposed to be inconspicuous, since it's not supposed to be a warning or a "mark of shame".
(I won't rule out adding a per-post warning for newbies if people evade the per-topic warnings, though.)