Oh My...Please simmer down oceanbeachsky. There are virus everywhere on the planet, including right there in your home town. Just be sure to wash your hands regularly and maybe bring some extra hand sanitizer. The ocean water is fine and just as clear as can be. If you are worried about the tap water just drink bottled water. I just returned and I can say that I drank tap water and I survived just fine.
The chopping was a altercation between 'family' members and did NOT involve a tourist. Just be sure to keep your head about you (hahah,no pun intended) and you will be fine.
As far as there being no good food in Negril all that I can say to that is WHAT?!?!?! One of my favorite parts of Negril is the food. Try, Kuyaba, Ivans, 3 Dives, just to name a few.
Just Chill out and enjoy the ride!!!