Yea, all his things are on public autochat. That's most likely the case.
Anyways bro, congrats! The money you're making from osbot is really good, just be careful! Staking isn't consistent
Selling RSGP isn't illegal, it's just against the rules of runescape. I'm not sure about skrill, but paypal reports your income to the government after a certain amount of money transferred to and from your account, so you will be taxed.