Heh, I was totally going to do this as soon as Book 6 ended. Felt like the right time. But since it's here now...

I suggest that resolved plot points should be removed from the main list and relegated to a spoiler tag at the end. To help with that, here's my list of points from your list that I think should be considered resolved, with some comments:

What is Vaarsuvius' gender?
As you said, genderqueer.

Do the crayon drawings hide a secret?
This is strangely worded, but I'm pretty sure what SV meant was: Rich has said that the crayon drawings aren't necessarily exactly what happened. Is there something more that we weren't shown? This was answered with the reveal of a huge number of previous worlds.

What are the nine sides of the conflict?
Now that the Linear Guild are out, we know that the "nine sides" comment does not mean there will be nine sides at the final battle, only that there are (at least) nine factions who play some role in the story. We've already met enough to fill the bill, so the comment has no further significance. (At the time the comment was made, it hinted at two factions not yet revealed at that point: the Vector Legion and Hel.)

Will Durkon become a normal dwarf again?
Well, yeah, that happened.

Where do Sabine's loyalties lie?
#804 was even titled "Where Her Loyalties Lie", so that was already resolved before Nale's death, but as you say, her outburst nails it.

What will O-Chul and Lien find at Kraagor's Gate?
Resolved.

Current arc plot points:
All resolved except the Godsmoot. (One reason why I was going to wait for the end of Book 6, to start with a clean slate.)

Will Hilgya come back?
Yes, although that creates a new unresolved plot point: What will be the fate of Hilgya and Kudzu?

And some comments on other points:

How will Belkar "die"?
The quote marks are not just unnecessary but outright wrong. The Oracle did not use the word "die", but rather a variety of euphemisms: "take his last breath ever", "should savour his last birthday cake". If you want to express doubt about whether these mean he will in fact die, then don't use quote marks, change the question to something like "Will Belkar die? If so, how?"

Elan's happy ending:
Word of Giant confirms that this simply refers to the work of fiction that is OotS ending happily. Maybe replace the question with something along the lines of "How will Xykon be defeated?" But... it's kind of obvious to say we don't know how the story will end before it ends, so I would drop this from the list altogether.

What happened when Roy and Durkon visited the Oracle the first time?
The reason why this is on the list is that, since Roy and Durkon are two, they could have asked a second question as well as "Where is Xykon?" In fact, they must have asked a second question, or they wouldn't have had to resort to dangling the Oracle out the window to get a third. So, what was that other question and its answer?