I've also done a full network replica (all the data indexed in a postgres) on a raspberry pi (with an 8tb nvme attached via a hat). Its really not expensive to do . And if I wanted to drop data older than say 3 months, it would be even cheaper still.
The default pds packaging takes care of SSL, but thats not a requirement, just something we try to make easy for users.
Also at:// URIs are of the form at://DID/..., and your human readable handle is bound to your DID through DNS TXT records _atproto.roshangeorge.dev, but applications all know to render that as just roshangeorge.dev. That DID points to a document that specifies where your server lives, so the HTTPS/WSS routes can live wherever you want them to.
Also likes/replies/etc on your posts go in their authors repos not yours, your intuition is correct there.
If you want an anonymous currency check out something like Zcash or monero. They use some fancier crypto to obscure transaction inputs and outputs, which gets you a bit farther towards being anonymous.