We need to be able to explicitly  merge records .  It's all well and good that the 'merge potential duplicates' is there but once you've decided to keep records separate, you seem to never have the opportunity to merge them again.

In real life it's rather common to not know a user is a dupe until they've been in the system a while.  By then, if you've not chosen to merge them, you are out of luck.   ...and why have a merge if it can't be used when needed?