Why do points 1 and 2 require strong engineering background? Knowing a feature is important or what features users actually want is not related to how hard it i

Why do points 1 and 2 require strong engineering background? Knowing a feature is important or what features users actually want is not related to how hard it is to implement or how long it will take. If you have a good relationship with your engineers, you should be able to talk to them and trust their input. Point 4 is the one that really sounds like needing engineering background.