That torrent is an “art piece” the creator made to raise awareness of NFTs. This video shows an interview with the artist who created that project: https://youtu.be/i_VsgT5gfMc

The first half of the video (and the overall reason for creating that torrent) is exaggerated and over-generalizes what NFTs are in order to claim “a problem” with them, but the second half does have a good discussion about the technology itself (educating users that scams exist in any technology, and because it’s new and different, there’s less guardrails to help users avoid scams automatically, so you need to be vigilant yourself).

To “pirate” a digital item is to get access to something you’re not supposed to (e.g. software you’re only supposed to have if you buy a license to it). Downloading the image of an NFT is just fine as it’s public content. If you then claim that image is your creation (claim to be the artist) or profit of it (commercial use) that’s more drastic. For many NFTs the graphic attached to them isn’t the valuable part of the asset (e.g. the access it grants, or the voting power it authorizes, or how it interacts with a digital game/space is the key thing that only the owner can do); you having a copy of the thumbnail image doesn’t change the abilities the owner has (and therefore the value of the actual token).

I’ll also vouch for Backblaze’s B2 plan; works well with Synology, and has great reporting options to let you know if you’re approaching your budgeted value, and web-based browsing tools to verify what data they got successfully sent to them.