Thank you, very interesting read.
I have some objections to 3.2 ("Don't bother with trying to run a website"). Yes, running a site on the same scale as mangadex would be very expensive. But for a scanlator group seeking to host their work only, probably will not be that bad. Storage and domain is dirt cheap. No problem there (which I think you acknowledged). Database, server, if you don't do anything stupid it should be dirt cheap too. Bandwidth... well, Hetzner charges 1 EUR per TB, as an example (iirc Hetzner requires KYC, but you see the point). Don't serve images to clients that are part of DDOS attacks and costs should be reasonable, again especially for the work of a single group. Website design "cost" shouldn't even be mentioned.
So most people can probably afford to run one, just as a hobby. Then if you assume ad revenue, and donations...
You have a good point about it attracting the wrong kind of attention. But nowadays you can pay for VPS and domain names with crypto. So worst case they take something down, you just take a day or two and change domain names and servers. Anna's archive seems to be doing well on this model, but they have very very good OPSEC. If you mess up somewhere you can end up like the comick guy, or much worse, the bato guy.
Furthermore, the mangadex DMCA takedowns have made it clear that we (readers and scanlators) cannot just rely on mangadex, nice as it is. Complying may have been the best decision for them, but it was a disaster for everyone else. If it was not for the aggregator sites scraping mangadex, a lot of work would've been lost. Now we must check a checkbox that we have permission, when uploading. I'm sure the mangadex team knows that the majority of the uploads would not fulfill the criteria. I'm not sure if I'm allowed to say anything further about that here.
Now veering off that topic, obviously this is a cat-and-mouse game. How do we move beyond mangadex and co, which are vulnerable to being taken down, and endanger the operators? I can think of two ways.
1. What we have now, except as Tor onionsites. Now, the operator is pretty much anonymous, so you can even just run it on a homeserver, unless some Russia/USA/UK/Israel-level state really really wants to get you, even more than they want to get terrorists and CP distributors. Tor can be blocked, but blocking is much harder than blocking normal websites. Downside is slower load times. Also, very few people use Tor, so there needs to be some kind of awareness campaign (in other words, this will be very difficult). I think this is a good thing to do parallel to the regular clearnet websites (offer both an onionsite and a clearnet site).
2. Host all the images as torrents, or other distributed P2P schemes like IPFS/Freenet/etc. That way other people can contribute their bandwidth, and even if the original operator gets shut down, it can continue. Now all you need is something like mangadex interface, but it is actually just a torrent tracker. That torrent tracker metadata itself can be distributed P2P too. So anyone can operate a frontend. And operating just the frontend would be legal in some jurisdictions (or so someone on the internet said). I actually saw one manga site use IPFS already... so maybe this is the way things are headed.