None of the metrics you chose are simple:
- Resting Heart Rate (lower is better)
Some evidence shows that this is not the case. Too low often indicates a low resting metabolism. This can be fine for a sportsman who ramps up the heart rate when exercising, but for an office worker, for example, there may not be the physical load to ramp up, leaving them lethargic/slow.
- Number of hours sleep per night (higher is better)
I am much more productive with 4 or 6 hours sleep than either less than 4 or more than 7. Just the way my body clock works - you'd need to work this out for each individual.
- Blood Pressure (lower is better)
Not necessarily - I have a colleague who has problems in this area. Blood pressure low enough that if she stands up too fast she sometimes faints. There is an optimum middle ground, which varies by individual.
- Body fat percentage (lower is better)
Again - this is variable. Some individuals are better suited to a higher level of body fat than others.
tl;dr The core message I have is: it's all variable. You'd need to define metrics per individual and circumstance.