3. You could say, "why he doesn't kill some ninja for fun or force Hashirama to fight him that so much he wants?" Well, Madara is of the old school. He wants to take his time with the things. He wants to fight with hashirama but while the later is at his full force and only when he has his complete attention. If he tries to attack him while the later is not done with the Juubi, then he knows that he won't have his full attention and therefore their fight won't be very enjoyful or fair since hashirama will have different things to care about.