Lifetime plans
Content rights are billed to the provider every month forever. A one-time payment cannot fund a recurring cost, so a lifetime plan is either a mispriced product or an exit strategy.
In practice it is nearly always the second one: collect a large up-front sum, then close.
Irreversible payment only
Cryptocurrency and gift cards remove your ability to dispute a charge. Providers confident in their retention accept cards because chargebacks do not scare them.
This is the single most predictive red flag on the list.
Messaging-app-only support
A Telegram handle is not a support department. It is also trivially abandoned, which is the point.
Look for live chat or ticketing attached to the domain you are paying, so there is something to hold accountable.
"You need a VPN for it to work"
A licensed service has no reason to care whether your ISP can see the traffic. A VPN requirement is a workaround for ISP-level blocking, and ISPs block what rights holders have asked them to block.
This one sentence tells you the licensing answer without having to ask the licensing question.
The rest of the list
No published refund policy; no uptime SLA; a domain that has changed more than once in a year; a licensing question that gets a vague answer; and a price under roughly $8 per month for a full US lineup.
None of these are about being unfashionably cautious. They are about whether the service will still exist in March, halfway through a season you paid for.