As has been suggested, you should try reading up on eugenics, and a sorry tale it is.
You also need to get rid of the rather sterile concept of "best". It has little utility in the context you are using it.
Let's take most of your desired traits, shall we?
Health: longest predicted lifespan, immunity do (sic) diseases.
These are not necessarily the same thing. Take malaria, for instance. Do you want your population to be resistant? Fine. Of course, if malaria is not present in a particular area, it's entirely possible that the inhabitants will suffer from sickle-cell anemia (which confers resistance to malaria). Actually, it's present in malarial areas as well, but its effects are a net benefit. Cystic fibrosis, a rather nasty genetic disease, is theorized to confer resistance to cholera, typhoid and/or tuberculosis. The list goes on. Look up "heterozygote advantage".
Mentally: ones that are mentally stable and have the highest amount of
the best chemicals in their brain for example serotonin, dopamine,
oxytocin, endorphins, and glutamate.
You are apparently unaware that "the highest amount of the best chemicals in their brain" is normally A Bad Thing.
High serotonin - Serotonin Syndrome. Extreme cases include high fevers, seizures, irregular heartbeat, unconsciousness, death.
High dopamine - agitation, anxiety, insomnia, hyperactivity, mania, paranoia.
High glutamate - hyperalgesia (pain sensitivity), restlessness, ADHD-like symptoms.
Mentally (2): best IQ along with how well they can adapt and absorb
information.
High IQ has only one certain benefit - it suggests that you will do well in college. That's it. It is what the IQ test was developed for.
Breeding for "intelligence" is one of those nebulous ideas which seem straightforward but in practice is very, very iffy. At the very least, "intelligence" seems to be the product of a whole bunch of genes (not the same ones in each individual), and I suggest you familiarize yourself with "regression to the mean".
At the very least, you should be aware that high levels of technical "intelligence" appear to correlate with autism rates. Are the Altums really interested in getting a lot of Aspies?
Genetics: best genetics means best survival in the natural world.
Oh, that's good. As we all know, "the natural world" is a nice uniform environment, where what it takes to survive means the same thing all over, right?
Wrong. At the least, the skills (and their underlying attributes) needed for survival are different between tropical hunter-gathers, plains bison-hunters and Arctic hunters.
Sex: the humans will compete for the best chance of the best mate.
Best chance? Best mate? US southwestern tribes such as the Pima are noted for exceedingly thrifty weight retention, allowing them to survive the inevitable drought/famine cycles in the area. Put them in a more hospitable environment and they become obese at a very high rate. Is a Pima woman a "best" mate? That does depend on exactly which version of "the natural world" you're living in.
In Darwin's TOE, he distinguished between natural selection and sexual selection. Natural selection applies to individual survival. Sexual selection applies to mate selection. The two are (or can be) in intense conflict. The peacock's tail is a prime example. It hobbles the mobility of the peacock, so a bigger tail means a lower chance of survival to breeding age. A bigger tail appeals to peahens, so a surviving peacock produces more offspring. There is simply no way to tell in advance what the optimum (in terms of overall peafowl population) balance of the two forces will be. The same applies to any such conflict.
Is being a murderer a good thing? One study of an Amazon tribe (the name escapes me) dealt with the nature of local warfare. This normally involves the two sides confronting each other and making scary displays until one side or the other backs down. Actual fighting is fairly rare - after all, if you actually get in a fight you can get seriously killed, and this is sort of the ultimate in undesirable genetic outcomes. The thing is, according to the study, the rare individuals who actually went and killed somebody in these confrontations had more children than average. In modern terms, chicks dig bad boys. Or, as the old Tom Rush song goes, "Ladies love outlaws".
So overall you might reconsider your premise. For the most part it makes little sense.