As you acknowledge, no one can predict the outcome, and the scenario you paint is as plausible as the one I imagine, which has a happier outcome for the daughter, Navy. There are lots of kids whose parents are of questionable character. While life can be hard for them, many manage to live respectable lives, and in many cases, they turn out to be far better parents than the ones they had.
At age 18, Navy will have the legal right to change her name to Biden and no one can stop that. If she sees it then to her advantage to do so, she would likely do that. A lot can happen between now and then, and further speculation about Navy's quality of life is a waste of time.
At present, while I condemn Hunter for being a deadbeat dad and Grandpa Joe for not acknowledging this innocent child for four years, I am glad circumstances have taken the turn they have. The girl will know who her father and mother are, and, as long as the mother proves responsible, and Hunter pays his child support, Navy and her mother will receive the financial support needed to raise a child in a financially secure way. That's more than a lot of children have whose mothers are single and parents have checkered backgrounds.
Regarding nude pictures on the internet, you're pulling out all the stops against Hunter, aren't you? But this point is a glancing blow at best. I'm old enough to remember life before the internet. And I remember when Jenny Cam or something like that first came out. A woman put cameras in her apartment and, for a subscription fee, people could look in on her live. That was headline news at the time and she made a ton of money. Immitators and innovators followed in droves. Since then, how many millions of people have put nude pictures of themselves on the internet (for free or for money)? How many have made sex tapes and posted those too? While I'm no fan if it, this behavior seems to be increasingly common and done by parents too.
I'm not sure this has a socially redeeming benefit. If I was a teen, I would fill ill-at ease if my friends were using their phones to check out my nude parents online. But what I think does not seem to matter. And what I think is probably quite different than what teens think these days. For people in younger generations (and some in my own generation), this is an increasingly accepted thing.
And besides, if Marjorie Taylor Greene finds it acceptable to blow Hunter's uncensored, X-rated, nude photos up to poster size and display them for public view in the U.S. House of Representatives, who are you to consider those photos as something bad to have online?