Is the vocabulary taught culturally accurate?

I have just begun studying Japanese, but I have access to native speakers. I tried to to use what I learn. "Anata wa" is not used much and is basically considered rude. The first lesson teaches "O genki desu ka?" to ask if the person is doing well. I learned that "O genki" is used after not seeing someone in a long time and mostly is used in letters to people. I am just curious to see if the site will distinguish between what is common and what is not.

Check out Sayaka's response in this thread:
https://members.rocketlanguages.com/members/forum/conversation-in-japanese/anata-only-for-family
 

I had the exact same thing come up using "anata" when I first tried using it with my Japanese friend. Ever since then I've been cross referencing with other teaching materials to make sure what I'm saying doesn't sound rude or weird. I can understand Sayaka's response as shown above but it would have been nice if that was explained in the lesson, especially since it's like the first thing you learn..