Usually it's the intake turbine wheel
that touches the housing causing wear. most probably from a worn center section bearing, this wear and resulting wobble can cause the center section bearing seal to leak and most probably this is where your oil
is coming from.
Bad news is that there has been some damage of course and that means that the efficiency of the turbo is decreased and you will see less boost and therefore some power loss.
Good news is that with a new center section bearing and seal, your oil consumption
from the turbo should be nil, you may have oil consumption
from valve seals
, rings etc from the engine