Jim,
Configuration should be.... skimmer --> pump --> filter --> other things like heaters, chlorinators etc --> return to pool.
Not sure about your comment
"You're saying that a sand filter could be plumbed into the return line, right? If it were plumbed into the suction side all the junk would have to be pushed into the pump and to the return when back washing."
If the filter was on the suction side there is no way to backwash.
As for the 1 skimmer and 1 return, not ideal but will certainly work. I'd aim the return jet off to the side and away from the skimmer to get better circulation.
Al


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