I'd like to know if it's possible to base this on js3-mode:
iEdit allows more interactive and visible renaming than query-and-replace
Even better if it can be made into a generic refactoring library
into which we can hook language support.
In addition? Possibly.
Since js3-mode is a fork of js2-mode, it should be possible to make a js3-mode translation layer. For methods that have just been renamed, a simple alias would do.
As for iedit, js2-refactor already uses mark-multiple which offers similar functionality.