Do these playoffs count as official matches? So do you lose win ELO in playing rapid tiebreakers? Also in blitz playoffs, such as the one in Norway Chess 2014, do they count towards official rating?
In general, yes, all of the games played in an official event count and can make you lose or win rating points.
For example, rapid tiebreaks in the World Cup count for the rapid FIDE rating, while the Armageddon tiebreaks count as blitz. In the Norway Chess, the classification process via blitz games also counts for the FIDE blitz rating.