Yeah that always adds the most story. Lots more potential for plot twists and what not.

Well, from what I've read, the goomy and deerling are important NPCs. They at least start the adventure. Though I find it interesting that the shelmet is not included in the trailer but has been mentioned elsewhere. Hm...

It appears the main village is called Serene Village. It's been confirmed that you do take the personality quiz to determine what pokemon you are, but if you don't like it you can change it. And when you pick your partner, you can pick if they are cool or cute (I'm assuming that means boy or girl). The first dungeon to be revealed is Foreboding Forest (much spookier name than prior first dungeons). The game supposedly starts with a deerling and a shelmet going into that dungeon after the goomy friend didn't return from said dungeon.