Now that we can edit icon-names to our heart's content without losing the connection between icon & name (that is, without seeing all instances of that icon suddenly pop back to the default), wouldn't that render this obsolete? Wouldn't you be able to go in and just edit as you like?

Because otherwise I'm not really sure quite what you're saying --- wouldn't "merge keywords together" consist of editing "keywordA, keywordB" into "keywordA & keywordB"?