1) Funnily enough, you can get all the Pokemon you listed in ORAS. Typhlosion can be gotten as a Cyndaquil as a gift, Rayquaza has to be catched as part of the Delta Episode, and Giratina can be obtained if you have Palkia and Dialga (you can get one in-game and trade the other from another game). Anyway, between XY and ORAS you can get almost any Pokèmon. If you want to see the newer the most, you should get X or Y, otherwise get Omega Ruby or Alpha Sapphire.
2) If you like good plots, BW and BW2 (especially the former) are absolutely a must. Otherwise, you can skip straight to the 6th generation.
3) It depends on various aspects: Plot-wise, Black and White were the best, but gameplay-wise, I play X and Y a lot because you can catch a lot of Pokèmon early on so it's perfect for variants. Also, XY are quite long, if you never played them before and you don't read a guide, which is a good thing, I guess?
2) If you like good plots, BW and BW2 (especially the former) are absolutely a must. Otherwise, you can skip straight to the 6th generation.
3) It depends on various aspects: Plot-wise, Black and White were the best, but gameplay-wise, I play X and Y a lot because you can catch a lot of Pokèmon early on so it's perfect for variants. Also, XY are quite long, if you never played them before and you don't read a guide, which is a good thing, I guess?
