Yes, it's legal.
Well it depends if your wife knows your facebook account and it is legal
it needs to access your facebook to get your name and to know if you are of legal age to access the site. It will need your info to sign you up and as your login.
Access to the internet, and most other media, is strictly censored in China. (see the related links below)
yes china do have facebook.
You have to be 13 to be on Facebook.
Facebook and Google will only get to China when the government lifts the ban.
You cannot access Facebook account using Gmail. You have to use it using the Facebook site only. Gmail is just for confirming the account.
Yes, you can access Facebook on every smartphone these days.
According to Facebooks rules, no-one under the age of 13 should be on Facebook, and those between 13 and 18 are only allowed access with parents permission. Therefore if you are underage, and you have a facebook account your parents have authority over it and may access it at their own discretion.
www.facebook.com
Can't access my Facebook account or email from facebook
Yes, that is the Legal Age to have a Facebook Account.