The ancient Greeks tried to use logic to understand the world. It was a good start. In the Enlightenment we found that experimental evidence was more important. Many of the logical Greek ideas were found to be simply untrue.
I'll start from the top. How do you measure "talent"? I'm not suggesting that there be a scientific instrument - any sort of measure, from "value added profit to a company" to "number of conference presentations" to "number of people in a random sample who say that X is talented".
You suggested that the number of neurons or brain plasticity might be important. We know that the size of the brain is not well correlated with intelligence; Einstein famously had an average sized brain. And while neural plasticity is a useful metaphor, it comes in many forms. Which do you mean, how do you measure it, and how strong is the correlation to talent?
We know that talent is extremely dependent on the environment. Consider Ronald Colman, who was a popular actor in the silent film era but whose career didn't take off until the talkies, when the audience fell in love with "his beautifully modulated and cultured voice", or Lars Hanson who believed that his heavy Swedish accent wouldn't do so well in Hollywood so moved back to Sweden. He was successful in the Swedish film industry, so by one measure of talent - made a living on his ability - he was talented, but by another measure - lifetime revenue - he was less talented than if he were better at English or of there were a higher demand for films with people with a Swedish accent.
Or look at the relative age effect (http://en.wikipedia.org/wiki/Relative_age_effect ) where talented sports players - defined as those in the upper levels of their respective sports - are disproportionally born in the early part of the year. The hypothesis is that as children these people were slightly bigger, stronger, and faster than the others in their cohort, so were more likely to do better, and receive extra training and support.
There are also systemic issues, which is the only reason I can think of to explain the decreasing presence of women in computing from its peak of 38% of awarded CS degrees in the early 1980s to ~18% now.
How do you disentangle the intrinsic talent portion that you think might have an effect from the large number of known environmental effects?
You posit that "we all didn't take care of ourselves as good as possibly others either due to laziness or unfortunate environmental factors", which does consider some environmental factors. However, the main part of the hypothesis is "we all didn't take care of ourselves". What does it mean to "take care of ourself"? How do we tell if someone is doing a good job of taking care of oneself, in such a way that it does not preclude talent development? If it can only be usefully measured in a post hoc fashion, then it's victim blaming.
(Failing to take care of oneself is an obvious problem. I presume you mean something more than maintaining a basic lifestyle, as many people do that and don't get labeled "talented".)
K. Anders Ericsson, for example, stresses the role of extended deliberate practice on expertise. Is "talent" different from "expertise"? If so, how? And what practices are better for talent growth than expertise growth?
Similarly, if there is talent that is somehow independent of expertise, how do people in general tell? For example, one famous Stanford report finds "that praising effort, not talent, leads to greater motivation and more positive attitudes toward challenges five years later". (See http://news.stanford.edu/news/2013/february/talking-to-baby-... ). The hypothesis is that if a child believes that success at X is due to talent, and doesn't immediately succeed at X then that child concludes that she/he doesn't have the talent for X so doesn't try. When it's more the case that success at X is due to effort and practice, not intrinsic talent.