Can you do this? If it's a race & class that hasn't been unlocked, do you have to unlock those to play? And if the gold acct has AoD, would the silver need it too?
Definitely yes to the AoD question, and probably yes to the unlock question. Both are flagged by account, not character. Even if your character was grandfathered on your gold account, it would probably be just that, grandfathered to the account, but maybe it isn't in that case.
The grandfather date is around Dec. 6 2011. If your character was made before then, you won't have to unlock class or race for that character.