•link to selected other posts of user  There's already one in which you could go to their profile and then click Show the last posts of this person.
•like a twitter feed  What for?
•feeling home   Are you serious?
•stuff that cannot be sorted elsewhere  There's off topic section already
•reputation  It already exist so no need
•create identity  For what?
•safe place to start posting without annoying anyone  So you could just farm accounts without the fear of being caught in case you post nonsense? Nope

All of these reasons you sited are not valid enough (like at all) and it could be summarized to off topic section already (except for the reputation part in which it has it's own subforum).