Integrity and honesty are alien concepts in the Arab world. It is very odd how they supposedly hold their honor at such high regard while at the same time completely disregard truthfulness as a value. For an Arab unless he gives you an oath there is no binding and no negative implication of lying or breaking his word. It is your fault if you believed him and let him trick you. Of course giving an oath only means anything between muslims and even then excuses can always be made for why it is justified to betray an agreement or that the "real" fault is laid on the counter party.
Yes, that's certainly true. Everything evil or ugly that Arabs attribute to Jews (big hooked noses, being obsessed with money, always being out to backstab and rip people off, scheming to rule over the whole world) are what is true of the Arabs themselves.
It's also true that Muslims turn on each other for the drop of the hat. For the slightest political or theological difference, they will say that someone isn't a real Muslim and is an infidel worthy of death.