Let's say I write a novel. In that novel I have a number of characters who do things as I determine they will do, what color hair or eyes they will have, what gender, where will they be from, how they behave, live, when they die, etc.
I write and they do as I wrote. There is no chance that any character in my novel will 'rebel' and do something that's not in the script, that I didn't put there.
My book will begin, develop and end as I envision it exactly as I wrote it. Nothing will change the outcome once the book is published.
Now, in my book I have a character who is envious of his neighbor. And, one day, in a fit of jealous rage, my character kills his neighbor. What should be my reaction to this act? How should I "feel" as the creator of the character and eveyrhting he does, including the murder, if it is entirely the product of my authorship?
Can I justifiably be 'angry' and 'disappointed' with him? Can I 'repent' for having created him in my book without blaming myself?
No, YOU cannot be justifiably angry or disappointed in him because he is a fictional character. You cannot love him. Of course it is completely different with God and us. We are real and God really does love us. That makes all the difference. God HATES sin, and even when He knows it is coming from us, He is still angered by it. As Dr. E. said, "God's anger is righteous". It does not have the flaws that our anger so typically does. God's anger is a good thing.
As for the allusion to God repenting for creating man, do you think God "repented"? I don't. If God repented, then that would mean He changed His mind. That would make Him mutable, and I was sure that the Orthodox strongly hold that God is immutable.