Is there a way to add Jade support in WebStorm‘s Configure Inspections?
You can get to Configure Inspections by clicking on the Yeoman lookalike in the right below corner 
Jade plugin is active, but no Jade in Configure Inspections:

Which is annoying because when you have a jade template with invalid syntax (forgotten comma):
button(type='button' class='btn btn-primary')
WebStorm does not complain, but I get a nasty error when compiling the template. It would be easier to detect such errors faster.
The Jade plugin has no hidden features that have to be enabled in magical ways; the error highlighting you want is simply not implemented in the current version. You’re welcome to file a feature request at http://youtrack.jetbrains.com/