Does tmobile charge you for facebook sms?
If your using wifi, no!
Tmobile data usage with facebook/instagram?
Yes the data connection is used once you have logged in.
Does facebook really charge for messaging non-friends?
Lol no, facebook is completely free.
Does it charge you to go on a Facebook or twitter app on a android phone?
Cain i activate a tmobile sim card with a purhased phone from tmobile?
yes but you would have to unlock your phone first than you can do it thats what i just did like 2 days ago