A helpful bit of related information:
You can add the following to any window just below the first Page tag to make it stay open when you hit the Escape key. (But it won't, for example, stop the target window from closing when the target dies or gets out of range.)
Code:
<Button IsCancelButton="true" Name="EscapeKeyBlocker"/>
(You may need to search for any other instances of IsCancelButton="true" in the file and remove them.)