I think you can use any valid email you like.
It's kinda like a facebook status, but on gmail.
You cannot create a Facebook ID on Gmail. Facebook ID can be created on Facebook via Gmail. The confirmation mail is also received on Gmail.
There is no liking system in Gmail service. Facebook Like websites have a system of liking. Gmail just deals in sending and receiving mails.
You cannot access Facebook account using Gmail. You have to use it using the Facebook site only. Gmail is just for confirming the account.
No, you can't delete Facebook using Gmail. To delete Facebook, you have to go on their website. Gmail just is an interface.
No, you can't see facebook Chat text in Gmail. Gmail is a mailing service only. Thus it cannot link Facebook chat with it.
No it won't. Gmail is from Google, which is a separate company to Facebook, and so there is no connection when deleting a Gmail account.
No, you cannot recover Gmail using Facebook. You have to recover it via Gmail only. Both of these are different organisations.
You can create a Facebook account via Gmail. This links Gmail to connect with Facebook. The mails that you receive from Facebook are on this mail.
One can disable Facebook notifications on Gmail by first logging into Facebook. Once logged in one must go to settings and then to notifications. Uncheck the boxes that say send confirmations to email and it is done.
Facebook's passwords are not accessible via Gmail. Gmail does not store passwords anywhere. The most it does is receive notifications.