Will all octopi (arms, no tentacles) and squids (arms and tentacles) still be under the octopus type, or will they be divided into octopus and squid types? I'm asking because I think sharks had been fish at one point?

Shark is not a precedent for any future creature type changes.

Would a tentacle monster I had never heard of have made me happier with Innistrad? No. SoI, BFZ, and many other planes have been ruined by introducing some alien threat that's contrary to how the plane is supposed to be. I thought the Phyrexians ruined Mirrodin, AVR ruined INN, Rise ruined Zendikar, and so on. Why does there have to be some cataclysmic contrasting change in the planes internal struggles? It's poor writing. Theros and RTR didn't have that.

We have a game about environments. How do we make one set in a world different from another? We have to have something impact the world *environmentally*. We’re not a movie or a book where we can focus on traditional plot or dialogue. We have to tell the kind of story a trading card game can tell, that Magic can tell, and that is environmental stories. We don’t control what individual cards any player sees so we gave to convey it with a wider brush over a swath of cards - aka we need environmental stories. It’s like complaining about a radio play having just dialogue and special effects. You have to tell stories through the strength of your medium. Telling stories that play to the strength of your medium is the exact opposite of poor writing.

Hey Mark! I just had a question about the new mechanic Surge that was previewed on Crush of Tentacles. I was a little confused on the wording so is Surge an additional or alternate cost? I assume it's an alternate cost, like overload, but the wording on the card makes it sound like an additional cost.

It’s an alternate cost.

If Wizards listens to our feedback, then why do the uncommon slivers in M15 still look completely like humans and animals with tentacles instead of what we got for Sliver Hivelord and Sliver Hive?

Not all players think alike. Some disliked the new slivers, some liked them. The creative team decided to give everyone some of the slivers they enjoy.