Ramses did terrible things, yes, I agree. Whether in the context of the movie you can understand his characterization or not is, I suppose, another thing. Another thing is is that he inherited a status quo, it's probably morally easier to uphold a barbaric institution just because things have always been that way, than it is to implement that institution in the first place.

But God, and Moses by proxy, was pretty much just as bad. I shouldn't think the slaughter of children is ever an acceptable means to accomplish anything. If God really did have the power to murder people, he should've had the power to magically free the slaves anyway, or spontaneously convert the Egyptians or something. Pointing the gun at the children isn't particularly endearing