I think he means the last scene in Shakugan no Shana S episode 4.
For #1. When I first arrived in this forum and AnimeSuki, there was a report about Shakugan no Shana light novels selling for around 7.5 million copies. Reaching that mark in (I think its a 6 year mark now?) that time period seems pretty sufficient for popularity-wise. The teaser for season 3 shows the bridge scene from novel 16, while the anime overall ended at novel 14 where Yuji dissappears and goes evil, while rallying about the Bal Masque when Shana and Kazumi look for him. That's practically volume 14 there, volume 15 is a flashback volume of a flame haze we haven't met. I believe they plan to animate that volume although it still serves no major purpose for story overall.
The only problem I have so far, is that they never did animate the dreams that Yuji has when he chats with Snake about what's happening in the world and if it's truly right. Slowly talking Yuji into his goals about creating a new world where Tomogaras can live without the need to feast off humans for power of existance.
My paragraph above explains volume 14-15. While I'm not all that knowledgable about volume 11-13, since I only remember up to volume 9-10 before the skip to volume 14 since second season already covered most of the novels even though it was majorly anime original. Then again, it chopped out development of other flame hazes that will appear later in the volumes.
I believe they worded their questions quite accurately to what they wanted. What dont you get?
Well not that many questions that I'm already used to. But there is quite the increase user-wise
Volume 22 is basically where the volume will end (Guess I was counting extras this whole time
), so when it releases before season 3 reaches its ending. Then it will be right there that J.C. Staff will have no excuse over not enough information from the volumes to finish it. So if they really want to tarnish their remaining reputation to dust and lose major profit then they can just go ahead and mess with season 3. Now if they want to rebuild their reputation, then Shakugan no Shana season 3, To Aru Majutsu no Index season 3, and a rehash of Zero no Tsukaima season 3 is their best bet to start.
J.C. Staff seems to have enough investment to pull through animation wise since they animated quite the decent amount of animes 2-3 seasons ago. Now if they didn't throw their money in a fire, then if they invest majorly into season 3 where all those Shana fans and potential Shana fans are waiting for. Then I have high hopes they will make a decent profit from it. So overall, I don't see any reason for J.C. Staff to just blow their own studio to the ground by screwing this up.