Think of how many ailments people wouldn’t have to live with if scientists could manipulate our DNA. We could look however we wanted without plastic surgery. No more diseases, no more sickness. Everyone could have great bodies without working out. Injuries would almost never happen because our bodies could be adjusted to not have the ability to be injured. We could have a bigger variety of hair and eye colors without hair dying or color contacts.
How long do you think it will be before this is a reality?
What you’re asking for is WAY beyond merely “manipulating the human genome.” In order to manipulate the genome to do something, there has to be a gene that does the thing you want to do, and there’s no gene for “the ability not to be injured.” I see us being able to solve things like point mutations with gene therapy in the not-so-distant future. However, creating a gene that somehow prevents injury and disease when we don’t know what that would be or how it would work… that is an entirely different animal than manipulating the genome.
I suppose scientists could “manipulate” the human genome right now, if they were allowed to. The specific examples you mention (avoiding disease, designer eye/hair/skin color) are probably decades off, but I imagine you could have your very own green fluorescent protein-expressing baby in relatively short order if there were no regulatory hurdles and you (and the scientists involved) were cool with the ethical concerns.
Better yet, you could have a baby that grows to maturity in half the time like this salmon. Think of the potential benefits! Diapers for only half as long. Think of the possible drawbacks! Not learning to use the toilet until they are twice their normal size!
I don’t think this is a question with a good answer, since this isn’t something that’s likely to involve some “eureka” moment where we go from incapable of doing so to master genetic engineers in a decade; just steady progress. We could if we wanted to manipulate it a little bit right now, just not very safely or usefully. In twenty years I expect we’ll be better; in 20-50 years we’ll be better than that, and so on, improving bit by bit as time goes on. So, you could rationally pick any of those poll options depending on what you meant by “manipulate the human genome”.