How is Yahweh not immoral?

[Drich]

Righteousness is an unchanging absolute standard.

Oops, I keep forgetting that one. You are right, there is a fourth argument.
There is just one [major] problem: Righteousness being objective does not make it objectively good.
Scratch that, there are two problems. The one where Jesus contradicts one of Yahweh's laws. (as in my previous post) If the law was objectively good, then why would Jesus prevent it from being carried out? (Note: I'm going to be gone for a few days, so I'll get back to this later).

Nothing has been condraticted. The old Law demanded Death to attone for sin. Christ died. With His death comes freedom from the Law as the only way to obtain righteousness.