I found an easy technological way (but not psychical one), how to leave Facebook:
1) Go to Facebook (maybe, the las time :))
2) Find "Account Settings" in the right upper corner
3) Click "Security" in the left upper corner
4) In the window "Security Settings" find "Deactivate your account" - the small link after all the links, klick
5) Explain FB, why you are deliting your account, fill in check boxes, click "Confirm"
There is very hard to find really good structured information about how does these Facebook applications' tokens work. After a collecting huge number of information from different forums I finished this puzzle problem and I have really simple explanation:
There are two main DIFFERENT access tokens:
1) USER ACCESS TOKEN
This token is very powerful and it gives you possibility to see all the information about this user. In the FB console application you are giving your user access token to application called "FB console" and for this reason it can show you all the personal information you want to see. This token can show you such a information only about the current user, who approve the access to this information. That's why you need to approve all the access to this console application. It looks so that you need to take care about your user access token, but the true is that this token works only few minutes and than the application need to asked for it once again.
This is not very useful and for this reason there is second type of access token.
2) APPLICATION ACCESS TOKEN
Application access token is not so powerful, but once you created it you can use it forever. With this access token you have access to Facebook API with your application. The thing is that you cannot see all the information presented in FB console, but only the really public information, which are able to get from Facebook.