Ralts and Honedge are not available at that point in the game; you can find them later on after the city restoration. Pokémon that can learn Shell Smash and are obtainable before the battle with Kiki are Shuckle, Magcargo, Crustle, and there's a 50% chance of encountering a Turtonator in Pyrous Mountain.
As for your last question, dawn stones can be found by mining the glowing rocks scattered throughout the region.