Yeah, scammers are abusing the self-mod and lock topic features sadly. It might be best restricting who can self-mod threads or in what boards this can be done. As for locked topics, maybe we should consider that once somebody locks a topic in the marketplace it cannot be unlocked by anyone other than staff. With that being said, these two behaviours are usually huge red flags of scammers though so it has positives and negatives.
3) ban from posting: they break rule 13 & 21" reported many times, Maybe Moderators do not accept pictures as proof ".
This isn't true. A screenshot of their rule breaking is the perfect way to prove such. I usually permaban them if there's solid evidence they're evading the bump rule as well.