Hiya LM!
To answer your question, yes, USA does show new reruns (a week or so after the episodes originally show on NBC) of two of NBC's shows:
Law &
Order :
Criminal Intent and
Law &
Order :
SVU . I believe the reason is because USA is part owner of the L&O franchise. I can't remember the specifics about the deal

, though.
Monk and
Karen Sisco must have similar arrangements with USA, and that's why they get airtime on cable.
I've only seen
JAG once or twice. I know it started on NBC but moved to CBS after one or two seasons. I like its spin-off,
Navy NCIS , a lot.
I hope you can persuade someone somewhere to put
Hunter back on the air!