It should be possible to invoke Replace action on
all opened files in editor.
There could be a new check in Replace dialog.
Changing subcomponent to "search"
I'm missing that very much! Please, add searching/replacing in opened files, it should be easy.
If you want to find (or replace) in a set of files, you can select them in the “Projects” or “Files” windows (CTRL + click), open Find dialog (Ctrl+F) and choose scope “Selection”.
If you think this way is not user-friendly, please re-open this issue.