Why don't we need to decline "Okul" here? Isn't this supposed to mean "School's rules"?
More like the "school rules" :) We accept both with and without the possessive suffix however
Are "hakkında" and "için" interchangeable in this case?
No and I cannot think of any situation off the top of my head where they are interchangeable.
Got it. Thanks!
"öğretmen okulun kurallarıyla ilgili konuşacak" da eklenmeli