The fact is, you really can't tell when they were last online, It's just the luck of coming on when they do! But you CAN sort-of guess by their "recent activity" if you go to their page you can see the last time they added a new friend, wrote on someone's wall, etc., this can give you a general idea of when they were last online.
No only your firends can see them. If you are talking about people of Facebook which you are no friends with then no. Your friends that do not have facebook can not see your profile or posts.
You can see your friends' posts on Facebook if they accept your requests to be their friends.
No, You cannot see the last time they logged in, but, you can see if they are online and you can chat with them too.
When you delete your Facebook account, no one can see it unless you login to it again.
you cannt cannt cannt cannt cannt you can not no no no no
The original purpose of facebook is to communicate our friends and to see the information of of your friends
That depends on the privacy settings used.
See what? Be specific
Well I hate to say this but you can't sorry.
Yes.
This service is not avialable on facebook.
There is no way to see a mutual friend friends on Facebook if their Facebook is private. You will need to add the person to see their profile.