There are a couple of benefits to credit cards (in the US at least).
- Protection: If some steals my credit card info, I can fight the charges with the credit card company (and am not out any money while sorting it out) . With debit cards the money is gone and you’re fighting to get it back.
- Rewards: most offer good cash back or point rewards. It means I save 2-3% on average compared to using a debit card
- Persk: Many cards will add coverage for car rentals or discounts just for using them for the purchase.
If you pay off the card each month you get all of those persk at zero cost. While technically credit card companies charge stores 2-3% for each swipe, in the US at least there is no price difference for the customer for cash/debit/credit.
Edit/TLDR: In the US it’s cheaper and safer to use a credit card (if you can pay the balance every month).
I think the easiest way would be to have two vlans on your local network. One that is connected to the internet and another that is local only. I think you’d have to switch networks when wanting to access the jellyfin server in that instance, but would negate the main issue, which is your VPN.
Edit: that’s about the most secure you can get I think. If you bought a different physical router to host it, you’d have about as secure a setup as possible.