I don't know why only S&M onwards as you could get cards from BKT onwards and still would be standard.N is so powerful and could help you so much...
The deck looks a bit weird without N, Sycamore... but is good, although I see too much supporters.
I would remove 1 Acerola, and keep just one Lady to add Prof letter, but that's not from S&M era...
Volkner seems good and you could play a third. Adding Nest ball you would be able to evolve MZones faster if Candy in hand, or vice versa. Evosoda would help with Raichu too.
Try to remove some Supporter to add more items that can help you. It will flow better. And a Pal pad would help you recover some
WE WANT LEGACY TOURNAMENTS BACK !!! If you also want it, show your support http://forums.pokemontcg.com/topic/55966-feedback-making-it-easier-to-get-the-cards-you-want/
My 1st pokémon VGame http://forums.pokemontcg.com/topic/59894-my-1st-pok%C3%A9mon-videogame-nds-diamond-story-and-help/
Foro en español, también existe: http://forums.pokemontcg.com/forum/2-español/