one more....

An-na>s yu’minu>na bi-anna-hu bi-la << pist}u>n wa la r?s^wa ma tqd?r ddi>r wa>lu wa kull wah}?d wa zh?r-u.

i don t understand the end: …without bribe, you can’t do anything and everyone…(does what ?)

That sentence is a mixture of MSA and Moroccan Arabic. As I said in my other response, tadwira is bribe. The formal MSA word for it is rashwa, and people may call it as well qhiwa. [Paying for someone’s coffee]
As for piston, it’s a French word meaning commendation. These are two of the main social and mentality problems in Morocco. I guess that you’re exploring that through your readings :).

So the translation for your sentence is:
People believe that without a commendation or a bribe, you can’t do anything. And each person may wait for her luck.

The last sentence’s translation is rather rusty. The point is although bribing is somehow necessary, but some people do not do that at all, and it might actually work for them… by luck!