1.

What does turn Alex me off about bullfighting?

The killing of the bull is the thing that really turns him off about bullfighting.

2.

What is Jack's answer about bulls?

He says that if bulls were not killed in bullfights, they would be killed for other purposes, or never be bred at all.

3.

How about Jack's feelings when he watches a bullfight?

He says that watching a bullfight makes him feel like he is experiencing a dramatization of some of life’s greatest emotions.

4.

What does Alex say about a conclusion to their argument?

He thinks that coming to a real conclusion to their argument is probably impossible.