Raymond Chandler's rules for authors

What does mystery imply?

Mystery is a factor in page turning quality.  Readers want to read on to resolve the mystery.  In the textbook: The Realist Novel  Dennis Walder quotes Raymond Chandler on the essential criteria for a detective novel. They sound a quite strict but Walder argues that part of readers' enjoyment comes from having their expectations met.  A bond of trust binds the author to the reader's expectations.  He says the rules are like the criteria which differentiate a sonnet from other poetic forms.although Chandler implies a murder, the rules could be applied to any mystery.

It must be: 

•   a credibly motivated event and quest to unravel  
• methods to unravel the mystery are technically feasible  
• Realist in character, setting and atmosphere [specific time and place]  
• A sound story as well as a mystery  
• Should baffle most intelligent readers  
• Simple enough to be explained towards the end  
• Solution seems inevitable once explained  
• cool, not passionate romance or violent adventure  
• [criminal should be punished]  
• honest with the reader [no tricks: time warps, etc]

I'm trying to keep these criteria in mind while writing a medieval medical mystery. While surprise is essential, reader expectations also need to be met.  Any comments?