What is the first part of the script doing? What are you trying to accomplish?
As said, if WinActive works for me.

Ctrl+D creates a duplicate in FastKeys and does not delete anything.

Your code works for me, do you have a speaker turned on?

Search is currently only available in the main window with a list of items.

Thanks, clearly explained. We'll put this request to our wish list for a possible future development.

Currently you are able to create up to 4 start menus in FastKeys. We'll see if we can enable more in the future.

Try opening a Window Information Tool from the Tools menu and check if Control/Text can be recognized.
If not, you would probably need to make a screenshot and use one of the OCR tools.

This is currently not possible. However, you could insert dummy empty items into the menu (for example Run command to non existing file) for the separation.

I suggest you use html formatting which is much more flexible.
You can use any of the html editors like this one
https://html-online.com/editor/
After edition simply copy the created html code to FastKeys.

This is currently not supported. Good idea though.

Have you tried Rich Text format? The editor is available.