I believe the Egyptian army is massed along the border to prevent the Palestinians for moving into Egypt not to start a war with Israel. If the people started trying to migrate to Egypt I believe they would kill them.
Agreed. Egypt would be crazy to try attacking Israel again. But these things can sometimes get out of hand, as if they had a will of their own. The Egyptian military must be told — in no uncertain terms— to return home beyond the agreed deployment lines. Now.
And yes, it seems very likely that the Egyptian military would shoot to kill any Arabs seeking to turn to Egypt from Gaza. This is part of the tragedy of the Arab culture nowadays.