If you’re talking about the names of the commands used, I think the short names can lead one to think they’re more universal than they are. They’re in some cases rather specific (but I haven’t seen a good writeup of capabilities and limitations – almost certainly one could not fit all of the details in the names).
At least the long repair description says it’s “Tries to repair” (and a rewriting of recreate has begun that possibly will also help repair, however I haven’t heard any news recently, so can’t offer you any details).
–list-broken-files sounds like it’s mainly a preview of –purge-broken-files, which I think are mostly done using easily obtained data such as the database and remote file listing. Testing remote files completely would require downloading everything, and rarely will anyone be willing to tolerate the time and transfer.
The TEST command of all files with –full-remote-verification is quite thorough – and maybe very slow. Longer-term, the hash capabilities that some storage provides may be a shortcut to limited better tests.
How often does duplicati test your backup archives? gets into that future idea and other sorts of testing, with different tradeoffs. Unfortunately, I don’t think there’s any test that actually tries a source file restore. This could help users who don’t try their own test restore, but could also fall victim to a huge source file.
It sounds like you might have lost a dblock file (thus the scramble for blocks), but do you have the actual error message? Sometimes exact messages can help find in the source the code that raised that issue. Restore is sometimes harder to get logs out of than backup though, but you can try pasting screenshots.
What’s the current system status? You were trying a full restore. Is there system damage in the picture?
Sorry things went badly, but with help from you, we can see if we can get the restore going better for you. How much of a hurry is this? Are you aiming for a recent version, or trying to get some historical version? Duplicati has lots of different ways to do restores (difficulty varies), and your needs can guide the choice.