Just to get the terminology right: the genome refers to the complete set of genes of an organism.

You are absolutely right about the hype that accompanied the sequencing of the human genome in the early 2000s. It was the result of the Human Genome Project (HGP), and I distinctly remember the news headlines of that time, envisaging the solution of all the chronic diseases (cardiovascular, cancer, etc.). Today we know that, first, there are hundreds of gene variants involved these diseases, and that, second, their interactions with each other and with the environment, the microbiome, and behavior are so complex that we can basically kiss this original idea good-bye.

As an aside, there are also less genes to the human genome than originally thought, but that is only of statistical interest.

The role of RNA is indeed an important one. While the so-called messenger RNA facilitates the translation of genetic information into the proteins that these genes code for, the majority of RNA is non-coding, that is it fulfills for example enzymatic purposes.

Your final question, wondering whether life extension is merely an extension of the period of suffering, is a very valid and good one. My personal interest is in, what we call the rectangularization of health expectancy.

While we observe a certain period at the end of life which is marked by deteriorating health and function, its rectangularization means that we extend the fully functional period as much as possible, thereby compressing morbidity into a very short period at the end of life. If we were to extend lifespan while simultaneously extending the period of suffering we wouldn't gain any quality of life. The latter is far more important than lifespan itself. At least in my view.