No, but you are making a comment that he is having some serious
problems, just based on his posts and language alone. It is never
right to make such observation about someone unless you know him
personally and you know him in and out to know that he has some
serious problems.
No, someone does not need to be sure whether he is close to me or
not, but once someone insults a person who is close to me, I will
definitely stand up for him/her, especially when such a personal
and sensitive judgement is passed. How would you feel if one day I
read your post and said,"Hey dude, there is something wrong with
you." How would your friends feel? Would they not say anything
about it, if they know that is not the case?