up daisy hannam`s bum, check out her website.
you can get it from patrick in route 520
you can only find it during swarms
you can't find omega
westhill
no omega is not a real pokemon, but arceus is considerd the omega pokemon.
route 501
No, you will need to trade for them or transfer them via Pokemon Bank to get them in Pokemon Omega Ruby and Alpha Sapphire.
route 456
You can find it near route 538 or 539 or on the swarm alert
Nowhere.
Pokemon lake is a good game and tppc is also quite good and you could consider Pokemon omega
Illumise in Pokemon Omega Ruby can be caught in Zorua at the park.