In Pokémon Alpha Sapphire, after you reach Lilycove City, Captain Stern can be found at the Stern's Shipyard located in Slateport City. He is not in Lilycove; instead, players must return to Slateport to continue the storyline involving Team Aqua or Team Magma. The shipyard is where you will encounter him after the events involving the Team's plans.
The hideout is northeast of Lilycove City. You have to walk down to the beach and then use the move Surf to get there.
in lilycove city in the giant store on the floor before the top floor
There is no roller skate item in Alpha Sapphire.
Get to Lilycove City, and once you defeat the Aqua hideout just to the northeast of the city, the wailmer will move, and you can surf east to Mossdeep.
You can catch Skitty in Pokemon Omega Ruby and Alpha Sapphire in the barks of trees.
You battle Kyogre for your chance to capture it in Pokemon Alpha Sapphire after you capture the groudon.
Magikarp
The places from Pokémon Ruby and Sapphire that remained in Pokémon Omega Ruby and Alpha Sapphire include the cities and towns such as Littleroot Town, Oldale Town, Petalburg City, Rustborom City, Verdanturf Town, Mauville City, Lavaridge Town, Fallarbor Town, Fortree City, Mossdeep City and Sootopolis City additional locations that remained include Mt. Chimney, Jagged Pass, Meteor Falls, Seafloor Cavern, the Lilycove Team Hideout for Team Aqua or Team Magma, the Harbor docks in both Slateport City and Lilycove City and Devon Corp.
Yes, Tm's in Pokemon Omega Ruby and Alpha Sapphire are re-useable
No, you will need to trade for them or transfer them via Pokemon Bank to get them in Pokemon Omega Ruby and Alpha Sapphire.
Houndour can be obtained by trading from Pokemon X or Y. It cannot be caught in the wild in Pokemon Omega Ruby and Alpha Sapphire.
You will need to trade for Weedle or breed Kakuna. Kakuna can be found only in the Safari Zone in Pokemon Alpha Sapphire and Omega Ruby.