To fully disable everything health tracking wise, you actually need to enable the S Health app on your phone.
Once enabled, open it, click on more (upper right side of the screen), then select Manage Items.
Go into goals, and if any goal is active, select it and cancel goal (bottom right).
Once the goals are gone, go to trackers and disable everything.
Go back to the main S Health screen, and pull it down to refresh. This will sync with the watch and delete all the goals in there.
On the watch itself, go into the applications wheel and find the Shealth app and open it.
Spin the dial all the way to the right, and you find settings.
Go into the Health Nudges and disable everything.
Same goes for Workout Detection
Set Auto HR to off
Set Water Target and Caffeine Limit to off.
Go all the way back out, then check your widgets, any running health widgets should be deleted.
Disable S Health on your phone again, and you should be notification free from all heath alerts.