Parliament can make any amendments in constitution provided the house has necessary votes. This right has been given to them and that is why Parliament is the highest law making body. As for multiple interpretations, that happens throughout the world and not limited to Pakistan
For example >
Judicial interpretation - Wikipedia, the free encyclopedia (Its about US Constitution).
I stick to my stance, PA is the architect of current disaster as it has made constitution meaningless with flagrant violations on regular basis. Result is we have nutcases like TTP now who are challenging the whole system. Legally (even morally) there is no difference if TTP or a General does a meray aziz humwatno.
Pray tell why democracy flourished in India? It faced far bigger challenges then Pakistan. Gandhi, Indra, Rajiv murdered while in power. Indian politicians are far more corrupt too, India had multiple succession groups yet Indian Army never thought to back-stab their own nation and jump into power. Why Pakistani Army was never able to resist the temptation even when Pakistan was better off in every way.