The Taeyeon-Tiffany rumour is more of a fan rumour than an actual rumour. It's really only talked about on fan sites, never seen it officially mentioned in any capacity.
Yea, the Yoona-Taecyeon rumours old. So don't know if it's still a rumour or not.
---------- Post added 2012-12-02 at 10:45 PM ----------
Not everyone, mostly bogans and people like that. The dregs of society.
No idea how long it's been going on.