The "dreamworld" and global battle rooms will be hosted on the above site. I'm not sure what all they are going to be like. Here is a bulbapedia article on what to expect.
This is for Princess Kumatora:
Electric is weak to ground. Electric doesn't do much damage on grass, electric, or dragon. Electric doesn't even effect ground. I would suggest you find a ground type, but Elesa's two emolga's are electric/flying, so that wouldn't work on them. Ground would work well against zebstrika, though. Rock and ice type pokemon/moves would be good. I defeated Elesa's whole team with my tepig, so maybe you could get a pansear/simisear and try that. Or maybe you just need to level up your pokemon, as boring as it is. You probably already knew all this but I hope it helped somehow.
Exadril has a massive resist list and if you have Sand Rush as an ability it will make you very fast during sandstorm. It is already incredibly hard hitting so the other ability, sand force, is just overkill. This pokemon is also immune to electric attacks. Rock moves will help you cover flying types. Chandelure is totally immune to fighting and normal attacks. It also adds a fire pokemon to your roster which is great against a great number of things.
The only thing you have to worry about with the above is water pokemon. You'd have to deal with them with your Dewott which is not great or Gothita/Scrafty. The other thing you COULD do is pick up an electric type or a non water vulnerable pokemon with a decent electric move instead of Gothita (Psychic). That probably means Galvantula (Electric/Bug) (http://bulbapedia.bulbagarden.net/wiki/Galvantula_(Pokémon)) or even better Raikou if you got one of Shiny ones off the Wifi givaway (you can transfer them using a special method before you beat the game).