I also run with two, as I wanted the most flexibility. Couldn't see playing a Mystic without two Shrivelings right out of the gate, for example.
They didn't announce anything new. There was a full-art promo for Unexpected Courage, and then there were two new cards designed by some of the fans that will be playtested and come out eventually.
25mm is so snug that you'll never get them out again without damaging them. 26mm gives you more flexibility (so you can get away with only buying 25, for example), and they won't slide around within the cases once sealed.
One play of the core set campaign is probably around 2 1/2 to 3 hours. Then, you can play through with different investigators and try for different resolutions. It's not uncommon to play through the core set half a dozen times or more.
Pretty much any premium sleeve is going to work fine for this game. As long as you stay away from the penny sleeves, you should be fine.
Cards abilities which refer to "clues at a location" only apply to clues which are on the location (the card) itself, not ones on enemies, assets or other investigators at that location. See Rules Ref: Clues, p7.
This is the ever-present dilemma of LCGs. You will always outgrow your storage solution as you buy more expansions. I don't think using the core box for storage is a good choice, as it's rather small, and you'll run out of space fairly quickly.
Yes, you would have to use your Dodge. The order of events say that the attack of opportunity damage triggers first, and then the action effect.
I haven't read much Lovecraft, and haven't read King in Yellow, so I can't really say too much about that. These aren't pulled directly from the stories, so I'd imagine at most, there would just be little easter eggs if you were more familiar with the material.
