As to raising shares, there would have to be a threshold as to just how much would be needed to purchase one share, and also be determined the number of shares that would be available. As to the rest, there could be the model that is used now, just using various incentives.
As to what a persons DNA could be used for, it will not surprise me that, in the future, whether near of far, that insurance companies will be requiring DNA testing as to part of their risk determining factors. Really, what difference is this than that they want a persons family history, except that DNA is much more detailed? I could completely understand, even though I do not like it, that a company sees that a persons test results show that they have a high risk of a certain cancer, that the company would adjust their policy to that person accordingly. They can guess that now, to a much lesser extent, through other tests and surveys. It is often forgotten that an insurance company's primary business is to make profit. If there were little or no profit in insurance, there would be very little to chose from. Now, as to how this pursuit of profit affects the price of healthcare, well, that is another subject all together.
One of my father's favorite sayings regarding insurance is "it's a racket and a scam." But, unfortunately, a necessary evil.