He's an old stubborn guy who doesn't understand much. His account hasn't been hacked, he's not a scammer (but don't put 1$ in his thing).
We have faith in you since you are a forum staff regarding the 'account' not being hacked. But how do you make sure he isn't a scammer or won't scam in the future? If something happens, then victims or forum users would blame you for your statement. You may have access to check whether the accounts change hands or not, but none of us would make sure he will not scam.
No need to create another flag, he won't understand.
Feel free to report him.
I think so, since his account is already tagged; a flag isn't necessary IMO. Just better report those posts that are not appropriate based on the main thread. It would be a paid shill, or he won the token.
I think his account should have a trust flag as well. Perhaps a type 1? New members and guest users are most likely to fall for his crap rather than some of us, the old members, in case some posts don't get deleted.
I think flag not yet necessary for now, already have negative feedback. If someone fall into scam then victims would create a flag.