Is it possible, when using an aggregation, to either sort (ascending or descending) or filter out aggregations with less then 2 records? I don't see a way to do this in the UI, but I may be missing it.
Greg - You can duplicate a field/column, and set the aggregation function for the duplicated column to 'Unique value count', then write a formula that checks this to detect any unique value count other than 2 and sorts/flags/filters those records for exclusion. The subset function SUBSET_UNIQUECOUNT may be used.
Please note that whenever you are writing a live formulae field that is affected by Aggregation or Grouping, the calculation precedence ('calculate then group' or 'group then calculate') MUST be defined. The aggregation function defined for a formula column/field should almost always be 'Formula result' rather than the default 'Sum' or 'Mean'.