I still do not understand how "stronger" is not included in the final conditional chain in Q2. How should I approach questions from now on with this nuance?

Do contrapositives exist in the "some" / "most" world? Like the contrapositive of Effective ---*M*-> Eccentric is just: Eccentric ---*S*-> Effective. I would not have to negate anything, right?

For Q3 can you say: half or more types of pasta are not made from wheat

For Q5, is it okay to say: “should be provided-> org + primary purpose” ?

I am going crazy. Why isn't the negation "if you are not friendly, then you must not be a dog" ?