<<What would be a more derogatory...? Suggestions for a new word?>>

What's the opposite of retentive. Append it to 'anal' and you've got the term you're looking for. Almost: you're looking for the shortened version, like "anal," for "anally-retentive." So, now that you've got your new term, all you've got to do is lop off the appended term and you're through -- the opposite of "anal" is "anal."