Your answers will be far more readily found on the Malazan discussion forums (link listed above). Hairlock is a mean and slippery and evil little bastard, and there's no telling what sort of nastiness he had planned for anyone foolish enough to work with him.
Quick Ben, of course, believes that HE is meaner, slipperier, more evil, and most importantly SMARTER than ANYONE, so he was willing to work with a monster like Hairlock.
But for definitive answers on all things Malazan, go to their boards. Every detail is illuminated, I promise you.