Whisk has Find/Replace that even supports regular expressions (thanks to OgreKit). It is currently only per-file though and does not have multi-file search.
+1 for autotag feature. I've tried VS Code, Dreamweaver, etc. and this is by far the best software for live preview. I use it daily for my web development. Adding either a plugin interface or features like this would make this software go viral IMHO.