True enough. Vidal, of course, has been instrumental in easing the pressure on the defence much of the time. Marchisio, as much fun as it is to bash him, has also greatly contributed with his "sticking to task, fewer risks" play.
About losing the ball - naturally we lose it most times in the opposition final third (Vucinic!), as it should be, what with the sheer number of opponents there. Unless we go through some unwanted personnel change in getting "workman-like defensive forwards" to help press there, or change tactics in general to push higher up, exposing ourselves in the process, I'm not sure how it can be cut out. Just seems to be part and parcel of the game we play.
If I'm totally wrong and it's just due to individual mistakes all over the pitch, incompetence, whatever (Vidal missing simple short passes now and then, Vucinic dialing it in from a daydream), then it's probably never going to change either. By a certain age players seem to have their characteristics and stick to them.
-edit. Further, if the regista of defence would cut out his Pirlo aspirations, our possession would increase 8% at minimum per game. Fact!