There is. Search by deck in Browse – select all – Cards > Toggle Suspend (but watch to make sure you are all being unsuspended instead of suspended).
Neither of those things can happen. As I said above, a card in Anki can only be in one deck.
So, I see there are multiple organization systems in Anki.
Yes, and they are quite distinct.
Decks are folders that hold cards (and other decks). Decks/parent-decks/subdecks are the unit that a study session is built around, and by which Options are applied to cards/study sessions.
Tags are applied at the note-level and carry through to every card created from that note. You can apply multiple tags to a note, and even arrange your tags in a hierarchy (just like for decks). For the sort of overlapping organization you’re talking about, you should use tags, not decks.
However, 100 of the cards in Deck B won’t show up in Deck B because they are counted as being in Deck A.
Back to your original question about what happens on import –
To understand this, it will probably help to grasp that what you’re importing are notes, not cards. [1] Anki then creates cards in specified decks for each note that is imported (based on the instructions in the note type). If a note already exists, it is either skipped or updated (depending on the import options you select).
But the existing cards of those existing notes are deliberately not moved to different decks. This protects your work – prioritizing any deck organization you’ve already done in your collection over the organization in the APKG you are importing. [2]
When the import is completed, the post-import report tells you exactly what happened with each note. That’s the best time to intervene and manually reorganize the cards from any already-existing notes that you want to move to the new deck hierarchy. See –
There is no such feature, but IIRC the updated notes will have their modification time changed, so you can sort by modification date to locate them in the browse screen.
Make sure you understand the difference between notes and cards. ↩︎
There is an open feature request to allow reorganization on import (and an add-on that purports to do that). If that interests you, you can add your support/use-case there: Relocate Existing Cards During New Import . ↩︎