I think that your description of ATproto relays is a conflation of the role of an AppView (or backend) in ATproto and a Nostr relay. Relays (by default) are not designed to be a permanent archive of content, and are really meant as content streams for backends to ingest and index appropriately. The storage cost is also overestimated, as people have begun to host third-party variants of the Bluesky AppView (which is partially open-source due to its dependence on internal code for some non-essential to microblogging functionality):
https://whtwnd.com/futur.blue/3ls7sbvpsqc2wThe note at the end about Bluesky being able to censor, verify and ban users from the protocol is also largely incorrect, with some asterisks as is for a complex system. The Turkish accounts that were censored were hidden from the platform in Turkey via the app's labeler system, which allows for "composable moderation". You can use this system to implement geoblocking in Bluesky clients based on your IP address when you open the app, which is what they did to ban those accounts from being seen in Turkey. The application of labelers (outside of Bluesky's main moderation service which the Bluesky-hosted AppView follows) is client-side, and any client that doesn't want to respect the default geoblocking behaviour (or implement mod labels at all) can just ignore it.
The Politico columnist that was banned from Bluesky has their account taken down from the whole network because their account was hosted on a Bluesky PDS, which could be (somewhat because, again, the default AppView follows a default labeler for displaying content through the AppView's API) bypassed by moving their account to another PDS that isn't operated by Bluesky. If your account was banned from Bluesky while also being on a non-Bluesky PDS, you would still have access to the ecosystem (and a half-working version of Bluesky that is basically a shadowban due to the default client and AppView conflicting with the labeler's takedown action).
Speaking of PDSes, they also do quite a bit more than just store user data. As an user's identity is dependent on a PDS to exist as a proper account, most user actions have to be routed through it to allow applications to store their data on-protocol and to authenticate the user.
The verification system is implemented through a record type (or "Lexicon") that is stored on an account that basically confirms that the record owner has verified the target. The system is also odd in that there are two types of verified accounts, "trusted verifiers" (think Twitter's business verification system) and regular verified accounts. Trusted verifiers are chosen by the client and can verify their own set of accounts, giving them the regular checkmark. Clients that haven't implemented support for the checkmarks or allow users to choose their own trusted verifiers can basically see whatever checkmarks they want, or just disable the system altogether (which is possible in the default client).
How Bluesky uses DIDs are... complicated. ATproto supports two DID methods for accounts, did:web and did:plc. Web DIDs are used mainly for services on the network, but can also be used for regular accounts. PLC is a more complicated system, which becomes quite obvious when you find out the original acronym meaning was "placeholder". PLC is (in regards to the general protocol) not a decentralized system, as its current iteration is a DID document pastebin with authentication and version history. I do think that the method's current centralized status can be mitigated somewhat (synchronization between various directories, then having a consensus system for establishing the validity of the documents' current states), but the system could always be replaced at any point to either incorporate new features or to choose a new model for how documents are publicized.
Sorry for the long read but as you see I've wasted way too much time into reading through developer posts and documentation, had to unload it somehow.