D. Wimsey reads detective stories because everything else has love or war in it. He is a crusader against violators of common dignity and worth. F. Early on, Peter takes on Bertie Wooster pose to disguise his intellect. There is a need to keep track of social background and relationships. Suicides allow punishment of those unlikely to be convicted.
Accidents are well prepared.
E. She has two types of villain. The totally unscrupulous who deserve quick, severe punishment. Those whose misdeeds reveal moral bankruptcy. Lawyers and juries are particular problems. Practical necessities of detective hero A. Must be in position to be brought into murder situation.