I just got pokemon X even though I never beat this; I abandoned just before I entered some electric cave. I plan to get back to this after beating X, but it's been two years since I last played, and I forgot pretty much everything about this game; how hard is it to just jump back in after forgetting everything?
Also, how do you trade for non unova pokemon in the GTS? From what I remember I couldn't find an option...
What happens if I connect to Wi fi using a DS other than the one I first connected from? I recall when I first did so a message told me to only connect using that ds.
Proud mayor of the new Funtown since July 7th, 2013 "All glory to dear leader"
Keep in mind that if you switch systems or change the system time/date, the 5th-gen games usually penalize you by disabling certain time-based events and Game Sync. (I don't remember which events are disabled, though.) The loss of Game Sync doesn't mean as much with the closing of the 5th-gen PGL site, however.
Also, this might be relevant: http://www.gamefaqs.com/boards/661226-pokemon-black-version-2/67496682 (I haven't tried to deal with online connections and changing systems, so...)
As for trading on the GTS, you can only ask/search for the Pokemon that you have "seen" - in other words, the Pokemon that are listed in your Pokedex. If you don't have the National Pokedex, yet, you can only ask or search for the Unova-only Pokemon.