I'll have a go - hypothetical answers though they may be, I don't think these questions will get confirmed answers from any source anyway...
why wasn't there a police inestigation? Because she didn't lay a charge (and Zaps/her employer would probably have been happy with that)
why was she paid 20K? Because she was offered it by Zaps/her employer... for damage sustained through an injury at work that was not her fault and might have been subject to a charge. (Why the excessive amount? Only Zaps can say)
why has Gallop demanded his resignation and then after a meeting with Zap turns around and says that he was pleased that Zap has accepted and aknowledged the error of his ways and is a first step in the terms of his future in the code. Gallop needs the code to take strong stances against inappropriate behaviour to women, and Zaps had previously led the way disciplining his clubs players. Gallop needed Zaps not to appear to be a hypocrite here, and (eventually) Zaps got that message and resigned. Like Matty Johns, Zaps will eventually have a future in league somewhere if he still wants to...
why have the Cronulla board cleared him of any wrong doing?? No idea of the terms of reference of that internal investigation... not enough detail has been released to judge.
why have Cronulla refused to comment regarding the above?? As above, thin on the detail. They seem to want to keep it that way as they handle the fallout and look to the future
why has nothing been said about the illegal taping of the conversation? Because it's not illegal
why have people like Trish Crews and Kaye Fitzhenry come forward in support of Zap?? Because they are sticking up for a mate