OK matt_hooks, I take your point about upgoing and downgoing blades. Will think about your contention that it has "nothing to do with slipstream on the rudder".
Being a bit of a purist myself, I can appreciate your objection to the use of the term "critical", if indeed it has such a specific meaning in the propeller context.
In relation to jet engines, you say "there's no assymetric blade effect, it really matters not a jot which way they spin".
Are you sure this continues to apply with today's massive fans, not always ducted the full length of the nacelle? If you are, perhaps you could explain why.
Phew, it's a bit late to be banging on like this! [Can't type fast enough.]
Chris