Concerning epigenetics and methylation, methylated areas of DNA can be worked out through with analysis. Demethylation occurs naturally with age and especially with lifestyle/environmental changes. A person can improve demethylation through proper nutrition and better health decisions. I know a few therapies are being explored and this whole area of epigenetics is under heavy study. There's hope, we just don't know enough yet about methylation or histone modification and other mechanisms. It's all in the works.
It isn't that we don't have the technology. There are groups that can sequence an entire genome in around a month, even less. At the place I work there are people working hard at making it available within weeks and for a little over $1000, the same people that were a part of the human genome project to begin with. The Y chromosome has been entirely sequenced many times, I don't know why you think that it hasn't been. It isn't far-fetched to suppose that children of the future, hundreds of years from now, will be involved in projects at school where they sequence their own DNA. If we can reduce the cost to just a couple hundred dollars then I can see us being able to sequence the genomes of our newborns immediately after birth, as part of their health record. We currently have enough information to be able to predict problem areas with software and that ability will continue to increase over time. I imagine we would be able to understand evolutionary changes better when we can sequence the genomes of at least three generations and at numerous milestones for each generation.
Aging is complex and reverse epigenetics isn't going to solve the problem of aging, more so the quality of life for a single person. Humans need to improve their lifestyles and environmental changes need to be made because any therapy is only going to be temporary if a person does not correct that. For example, a person that was malnourished, abused, and endured prolonged suffering throughout childhood can amend some of the methylations naturally through time with better health and lifestyle decisions. Even then, parts of their DNA are still vulnerable to methylation reoccurring. I wouldn't consider those areas bad arrangements. The bad arrangement is usually more concerned with the external factors of a person. That's why nutrition, fitness, lifestyle choices, pollution/environmental problems, stress factors, mental health, sleep hygiene, etc. are so important and stressed by the health community.
Our species is going to blip out one way or another. Having children can be a joy and most people do it without the intention of continuing the species. Prolonging our lifespan without improving our quality of life is disastrous. Many people don't want to live past 80 or so.