The free will part is the most interesting if you look at it from a systems level.
How can there be randomness in a predetermined system?
Let me elaborate. You have two boxes. In each box is a creature, imma call it a Smeep.
Smeeps can only do two things. They can either roll to the left, or roll to the right. They can do nothing else. And smeeps will only move when being observed. Each box contains an identical Smeep.
There are two observers of each box. This observer is the “prime observer”.
In the first box, the observer knows that their smeep can roll left or right, but does not know which way it will go. The second box has an observer that knows exactly which way the smeep will roll every time it does it. In fact, he doesn’t even need to observe it since the outcome is already predetermined.
I would argue that the first box is the “free” system. The smeep in the second box does not have “free will”, because it’s movements are entirely known by the sole prime observer of the system.
Biblical free will is the same thing. According to their doctrine, we exist within gods plan and everything we do is only done through God as the prime observer and prime mover. Meaning your actions are effectually predetermined and preknown by the singular prime mover.
God will always know which choice you will make. There is no free choice. Because if there were, then God would have to have some ambiguity on the outcome of your actions. Which he does not according to doctrine.
Ergo, it’s not free will.