DNS resolvers would be like relays, the user chooses which to add (1 or more). Some resolvers might be free, some might be paid, some might handle different chains, etc. DVMs, essentially.
For DANE and TLS fingerprinting is one or the other. If you're doing TLS fingerprint then no need for DANE. In both cases they are self signed certificates (DANE-EE if DANE). Also it's the TLS pub key that gets fingerprinted, not the whole cert, to allow for updates.
The key is (I think anyways) is that ICANN or not ICANN you will always need a source of uniqueness for human readable labels that can link to records, and there are only two ways to get that in a decentralised way, blockchain or some DHT-based Frankenstein. So blockchain it is.
But yeah, it adds another layer and I don't know if it's worth it, I think perhaps not. I actually think ICANN is pretty okay as far as systems go, they get an unfairly bad rap here sometimes.