Interesting thread Star,
As to 2nd up, my observation is in fact contrary to what you might expect if you believe a horse has been flattened by a first up run. Although I've not taken stats on it I believe that a first up 2nd or 3rd beaten less than say half a length bodes well for the next start whereas a greater beaten margin does not.
But the most outstanding (by far) elimination criterion is price fluctuation. If you're looking at the pointy end of the market any serious drifter, especially if there is a serious shortener in the same race, should be wiped.
Obviously this cannot be applied until just before the jump so maybe it's your eleventh elimination rule.


Cheers
Ron