Earlier quoted context omitted.
I agree with you entirely. Implied death threat (to him) sent to his wife from someone whom he has now gotten imprisoned who knows where he lives and confirmed it by sending a card... he seems awfully calm about all this and perhaps half-jokingly states he'll visit Fly in prison to meet him in person. I'd be getting placed under a witness protection program (is this even applicable?) and relocate. Move somewhere that…
I doubt it, this isn't a drug cartel kingpin or mafia don we're talking about. He's just a troll.
I guess thinking about it further, the 'good' news is that if the criminal was successful at what he did and had a couple grand to hire a hitman - he wouldn't have needed to crowdfund the heroin. So you're right in that it's more likely a small time, not-black-market-rich troll rather than someone more dangerous.