Salam
Quran "You did not throw when you threw but Allah threw", "you did not throw" technically contradicts "You threw".
Allah (swt) obviously has all perfections. Perfections are not only many but even infinite. Imam Zainal Abideen (a) says "o who's there is no bound to the glories of his face".
The issue is we agree but are arguing semantics. Semantics is just to convey an understanding.
Punishing is different than rewarding. Obviously that is true.
What is subtle and what I'm trying to convey, is the same exact reality that makes God compassionate and generous in rewarding believers, is the same, reality that makes him severe in punishment to disbelievers.
As you said, God's Essence is One. This is what I'm talking about. But what is the reality behind God's titles and aspects. They are manifesting his essence.
Quran says God is one in Surah Ikhlas which is different then when it usually says God is One. When it usually says the context is there are no equals to God, but Surah Ikhlas ends with that remark, while, the truth, is God is One means his essence is single and undivided. We agree on this.
Samad though means he is filled and lacks nothing, and so this where yes, there are from our perspective diverse attributes. But from Allah (swt) ultimate sight of himself, there is but a single essence. We need a lot of descent of glories to perceive aspects of God, but that is not to say, that his essence is actually divided.
So if we agree, then it at this point, just a dispute of how to use semantics.
It's as if to make analogy "You did not throw when you threw", to argue about whether Mohammad (s) should be said to have thrown or not. Both are true, he did throw and he did not throw, but it's about understanding what is meant by these two apparently contradicting statements that do no contradict.
I agree with you saying God is his Attributes is another way of expressing that. God punishing is different than being merciful, but it's manifesting in reality the same glory.
What I mean by his attributes all contain each other, is not that they actually each other when we think about them, but that they point to a reality of truth (God) that is referenced by all these attributes in a single undivided essence.
So we agree, and really, this is arguing about nothing at this point.