If I view a vocab list that I'm studying and it says "100% added", does that mean that I have seen everything in it at least once?

Or does it mean that it's all in the queue, but there may still be items I haven't actually seen yet?

100 percent added means you have seen all the items at least once.

the whole list is added.

I believe that 100% means that you have seen each item (character or word) at least once, but not necessarily every specific part of each item (reading, writing, tone, definition). Other parts seem to remain in the new item queue even though the progress bar lists 100% completion.

So for example, you may have 100% of a list added according to your progress bar, and you will have seen at least part of every character/word, but you may continue to see new definitions, tones, etc. added from the "100% added" list for a little while.

Cool, I hoped that's what it meant. Got exams coming up and I'm cramming lists!