It’s as simple as this: you’re free to make a choice, God just knows what that choice is going to be. There’s no intervention like
@BebsiBolice mentioned.
You’re contradicting yourself when you say “God has no freewill because he can’t change his mind since that would create a paradox in that it conflicts with his Omni powers”. If God does have Omni powers (i.e. he has absolute knowledge of everything, past & present), why would he need to change his mind? Surely he’ll always, without fail, make the choices that are the wisest and most befitting for the Lord of the world.
You have very little understanding of Qadr. I’m not going to go in depth with you in this subject, I’ll keep it concise. You cannot base your decisions on “what is written for you” since you have no knowledge of that, your duty is to strive to do good works. Allah has foreknowledge of the decisions that you’re going to make but the choice is yours. If I slap myself this second, sure it was written for me, but it was also my own doing. Qadr is basically you making decisions by the permission of Allah (whilst he already has knowledge of the actions that you’re going to make in advance), hence it was written for you.
That’s honestly a very stupid question. Being unable to be incompetent is actually indicative of absolute power rather than the contrary. If we say it’s impossible for Allah to forget something, is this a weakness or a mark of omnipotence? Allah cannot forget anything, thus he’s the all-knowing and all-aware, capiche?