I am yet to read the novel, although I have heard good things about it. But, this is EU after all and if not mentioned in any films or by Lucas it is debatable. However, I don't doubt their was anti-alien personnel in the empire's service. As for Palps wanting peace, I believe so. Only his version of it. For example, take Hitler (whom I believe Palps and his Empire/Reich is based upon, the similarities are scary!) when he came to power he wanted peace and order. However, this was at the cost of discriminating against those who he saw as the enemy: Jews, Gypsies, Homosexuals ect.