We can't merge accounts any more. We basically use a duck test + a quick look at whatever PII we have, and pass it up to a CM. There's nothing that a regular user can do. In many cases I actually suggest OP request a merge themselves just to ensure they're aware of it. There's been cases of folks creating what seemed like a endless stream of new unregistered accounts on other sites.
Duck test is good enough for edits. We can always roll back if your duck is actually a mutant possum.
I don't actually know the effect of pending edits on account merges, so just approve if it seems appropriate.