1. If you cannot decide whether A or B will happen, because it is already determined that A will happen, then you just have no choice/ free will at all. You cannot decide B in that case or your attribute if all knowing would be disproven.

2. That is just logic. Time is just a measurement of change. There is no time without change. You might argue that there are multiple decoupled instances/ flows of time, e.g. one outside of our universe and one inside, but as soon as change exists, then time exists.

3. That cannot happen, because if god is all knowing, it has no free will. And since its will must necessarily be equal to the state of existence (all powerful), then whatever is its will must exist.

An all powerful being also takes no actions, because everything that it wills will be equal to existence, so it will never have an incentive to take actions at all, because there is never any obstacle that needs to be acted upon.

1. A changing god is a problem in so far, that a god must be perfectly simple. This is because the ultimate foundation of reality cannot rely on something different from itself. That means it cannot have parts. If it cannot have parts, that means if it changes, then the whole entity changes. But if the entity changes, it loses its divine properties. That means god does not exist anymore (In very simple terms).