The Gym Leaders in Pokémon Black and White are Cheren, the Gym Leader of your home city, Aspertia City. Cheren uses Normal-types. Roxie, the Gym Leader of Virbank City, she uses Poison-types.
The third leader is Burgh of Castelia City, he uses Bug-types. His party consists of Swadloon, Dwebble and Leavanny with his Leavanny being the highest one level-wise because it's Level 24.
The fourth Gym Leader is Elesa of Nimbasa City, she uses Electric types. Her party consists of Emolga, Flaaffy and Zebstrika.
The Fifth Gym Leader is Clay of Driftveil City and he uses Ground-types. His party consists of Krokorok, Sandslash and Excadrill.
The Sixth Gym Leader is Skyla of Mistralton City and she uses Flying-types. Her party consists of Swoobat, Skarmory and Swanna.
The 7th Gym Leader is Drayden of Opelucid City and he uses Dragon-types which would include his party Pokémon of Druddigon, Flygon and Haxorus.
The 8th and final Gym Leader is Marlon of Humilau City, he specializes in Water-types and his party Pokémon are Carracosta, Wailord and Jellicent.
The Gym Leaders are Roxanne, the Rustboro City Gym Leader that specializes in Rock-types, Brawly the Dewford Town Gym Leader that specializes in Fighting-types, Wattson the Mauville City Gym Leader that specializes in Electric types, Flannery the Lavaridge Town Gym Leader that specializes in Fire types, Norman the Petalburg City Gym Leader that specializes in Normal types, Winona the Fortree City Gym Leader that specializes in Flying types, Liza and Tate the Mossdeep City Gym Leaders and Wallace the Sootopolis City Gym Leader.
You can catch Skitty in Pokemon Omega Ruby and Alpha Sapphire in the barks of trees.
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.
These Pokemon can be found before the National Dex: Latias (Alpha Sapphire), Latios (Omega Ruby), Kyogre (Alpha Sapphire), Groudon (Omega Ruby), Regirock, Regice, and Registeel. These Pokemon can only be obtained in the Delta Episode: Rayquaza and Deoxys. Post-National Dex Legendary Pokemon are: Regigigas, Ho-Oh (Omega Ruby), Lugia (Alpha Sapphire), Heatran, Mesprit, Uxie, Axelf, Palkia (Omega Ruby), Dialga (Alpha Sapphire), Giratina, Cobalion, Terrakion, Virizion, Reshiram (Omega Ruby), Zekrom (Alpha Sapphire), Kyurem, Raikou, Entei, Suicune, Tornadus (Omega Ruby), Thundurus (Alpha Sapphire), Landorus, and Cresselia.
No
It is not yet known if there is a building location for the GTS in Pokemon Omega Ruby and Alpha Sapphire.
The ability of Mega Diancie in Pokémon Omega Ruby and Alpha Sapphire is Magic Bounce.
go to map land 6 but you must beat all gym leaders including the elite four
Yes, all the TMs that were in Pokemon X and Y will be available as TMs in Pokemon Omega Ruby and Alpha Sapphire.
No, there are no roms for Pokemon Omega Ruby and Alpha Sapphire currently nor a working 3DS emulator. (They are also incompatible with the Desmume emulator.)
all of them
There is none