I could have sworn that I read somewhere after your very first LFR adventure you could freely change anything about your character, only once. I can't seem to find this in the campaign standards; can someone remind me or tell me I'm crazy 
I could have sworn that I read somewhere after your very first LFR adventure you could freely change anything about your character, only once. I can't seem to find this in the campaign standards; can someone remind me or tell me I'm crazy
No, that's not a rule. Once you start your first adventure, the only allowed changes are pursuant to the retraining rules.
However, it is not uncommon for gaming groups to turn a blind eye to this. In particular, when a player who has never played LFR before shows up (and most particularly when they're unfamiliar with 4e altogether), some groups may give them a pregen for their first game and tell them they're free to make changes after the adventure when they have a better understanding of how things work.
You might also run into ex-Living Arcanis players who are used to the recycling rules from that campaign (which, IIRC, let you remake any character before 4th level), and continue to allow that despite it not being part of this campaign.
Per Chris Tulach, I suppose you could always just claim you were working out an alternate solution to provide an appropriate play experience.
RPGA rules enforcement is more a function of social norms than anything else: whether your group considers certain behavior to be unethical is often more important than whether or not it's strictly speaking against the letter of the rules.
If you allow this in your group, I would suggest making clear what the limits are ("Whatever you start your second adventure with, that's final. Any other changes have to be through the retraining system.") to avoid the problem of people pushing the boundaries further than the rest of the group is comfortable with.
You're thinking of the "Class Retrain" feature in the CCG:
Class Features: When you would normally make a
retrain choice, you can instead choose to take a class
feature retrain. When you retrain for a new class feature
(and only for a class feature), you are able to retrain up to 2
powers and 2 feats with the class feature retrain. Each
character is only allowed one class feature retrain. If you
choose to retrain in this manner, make a note of it on your
adventure log.