1. Go to the status bar -> Availability

if you change the status line there and you configured a facebook account using jabber(@chat.facebook.com) then it does update your profile.

2. yes that happans to me also, proximity sensor is also something with similar issues(especially with Shortcutd) - reboot solves that.

3. You should try MyContacts and see if it suits you better, you can organize your contacts quite nicely with it.