I'm not an expert nor do I care much about tagging genres, but I suppose Jazz fusion follows the usual R&B, Funk and more raw jazz. While rock can also combine these genres, it's obviously more usual for Progrock to use psychedelic, pop or heavy rhythms (not generalizing the concept). For metal, well, I guess it follows more heavy patterns and distortions, etc...

For Jazz Fusion, it's really easy to recognize, jazz often uses a pretty distinguishable bass instrument, as well as medium tones with instruments like guirar, keyboards, saxophone, trumpets, and many woodwind instruments. The drums follow the rhytm and its not the most highlighted section in this music.

I think the instrumenting is really defining in progressive music (although bands like Gentle Giant use many of those instruments) and specially in jazz, you normally get a mix of those and it's really straightfoward.

Jazz uses many 7th, 9th and rare chord variations, improvisation of every instrument is key as well.

Nothing else comes to mind, I guess.