Nagging question about Grant Morrison's Happy (SPOILERS WITHIN)

Hi everyone. I signed up for this forum to specifically ask this question because it's been bugging the crap out of me.

I read Happy by Grant Morrison recently and really enjoyed it. But I could not, for the life of me, make sense of a pretty important plot thread and I was wondering if someone could explain it to me. (I gave Morrison the benefit of the doubt and kept reading, figuring I was just missing some small detail, because Grant Morrison is an amazing writer and would not let such an obvious plot hole slip through.)

(And in case you didn't catch it in the topic title, SPOILERS will be discussed here.)

Okay, I'm gong to recount the events of the story as I understand them. Tell me if I'm wrong.

Me. Blue hires Nick Sax to kill the three Fratelli brothers, who happen to be his nephews. Gerry, Tony and Paulie. And Sax decides the best way to get them in a room is to hire THEM to kill him.

Blue contracts for these three brothers only. We know this because Sax is surprised to see that a fourth Fratelli brother tagged along with them. As such, Blue did not intend for Mikey to die, it would seem.

Mikey is upset about the death of his brothers and starts firing at Sax. He runs out of bullets and Sax has him at gunpoint.

Mikey says there's money from when his grandpa, the Fratelli don, died. Only him and his brothers know about it. He tries to bribe Sax by telling him he's the only one who knows the password for the account.

Sax shoots Mikey. It is unknown whether he actually learns the password to the account.

A dying Mikey tells Mr. Blue that "sax knows" about something but does not explicitly mention money or a bank account.

Later Blue says that sax only contracted for the three brothers and that he must have killed Mikey "for sport." Again, it would seem Blue did not want Mikey to die.

Then, Blue says he and Mikey were going to split the don's money down the middle.

Here are my questions:

If they planned to split the money, why is Mikey so upset when his brothers die? And why would he even go with his brothers to Sax's apartment in the first place? If they planned this out, why would Mikey keep the password a secret from Blue? Did Blue plan this without Mikey's consent? Did he plan to take out the brothers and then convince Mikey to split the money with him later because he knew Mikey wouldn't approve of his brothers' murders?

And did Sax actually learn the password, or not?

Am I crazy or are there some inconsistencies here?

Thanks for reading everyone!