That is what I had thought, and was referring to. They can revoke their offer to license.
Yes. But this has no real effect, because existing contractual parties retain the right and obligation to sub-licence WoTC OGC (along with everyone else's OGC).
WoTC's legal argument appears to hinge on Section 9 and the word 'authorised'. But their argument appears to be so weak, that I can't think of how to set it as a Contract problem question for my PG Law students - and I've been trying!

Edit: And Lisa Stevens/Paizo are clearly aware of this. And Lisa at least has the deep pockets to defend and almost certainly win any action brought by WoTC on this.