By leveling It up to level 16
Actually Pokemon Omega Ruby and Alpha Sapphire is not out yet, but I strongly believe Bulbasaur will evolve at level as usual I doubt it would change dramatically.
It evolves by happiness
Ponyta evolves into Rapidash starting at level 40.
There is no roller skate item in Alpha Sapphire.
Yes, a Pokemon that has been stopped from evolving will continue to attempt to evolve until it reaches level 100.
Swablu evolves into Altaria at level 35. Altaria can mega evolve in Pokemon Omega Ruby and Alpha Sapphire when it is holding a Altarianite during a battle.
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.
Goldeen evolves at Level 33 in Ruby, Sapphire, FireRed, LeafGreen, Emerald, Pokemon X and Y and Pokemon Omega Ruby and Alpha Sapphire.
Magikarp
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.