Here are verses that speak of the very nature of God and you haven't answered a single one of them:
The verses which speak of the very nature of God forbids the thought that He repents or changes in any way:
"For I am the Lord, I change not" ( Mal. 3:6).
"I the LORD have spoken it: it shall come to pass, and I will do it; I will not go back, neither will I spare, neither will I repent" (Ezek. 24:14).
"With whom is no variableness, neither shadow of turning" (Jms.1:17).
"God is not a man that he should lie; neither the son of a man that he should repent" (Num.3:19).
You fail to distinguish between verses that speak of God's nature (which should be taken literally) and verses in a narrative that show Him repenting (which should be taken in a figurative sense).
Your approach is inconsistent and you must ignore or change the meaning of the verses which speak of His nature.
Yikes, prooftexting, batman (you are not stupid, but can be stubborn). These have a context and fit with Open Theism. They talk about God's constancy of character vs fickleness (cf. Jesus same yesterday, today, forever does not mean he is absolutely immutable in light of the incarnation). They also talk about specific times when it would be unwise for God to change His mind, so He does not. The changing mind motif (39x) only has to be dismissed as figurative to retain your wrong view. They can be taken at face value (and should be, since they would convey no truth even if figurative or negate a way to say God changes His mind if He theoretically did) if you change your view to a more biblical, coherent one.
Stating your view forcefully and disparaging other views does not make you right (I am learning). God is personal and you are reducing Him to a Platonic, philosophical idea.
The simplicity of Scripture should be enough to make the lights go on (you illustrate how far people go to not take things at face value if they do not match wrong views). If not, there are many academic articles dealing with these things. Don't confuse nature/being with volition. His attributes of wonder unique to Himself (omni, eternality, etc.) are different than His personal attributes (will, intellect, emotions, etc.). God can and does change His mind in some cases, while in other cases, He refuses to change His mind. I can take I Sam. 15 literally, but you must arbitrarily make one phrase literal and the other figurative despite no exegetical cue to do so. Change your view, not the Bible.
The other dual motif of Open Theism (similar idea) is that some of the future is settled/known, while other aspects are left unsettled/unknown by God. Calvinists proof text one motif and make the other one figurative, just as you are doing in another area. Open Theists are more consistent (we also recognize figurative language, but only when demanded by the context; normative literal is the way to go usually) and affirm the literal texts in both cases. Change the wrong view, not Scripture (clinging to a wrong view of sovereignty, free will, predestination is flawed if a more biblical view is available that can take clear verses at face value). Don't underestimate the philosophical, Augustinian, etc. influences on some areas of classical theology (relating to God's attributes and ways). You are non-mainstream on MAD, so jump in this one to test it...the water is warm (er).