FicWad

Yes, Madara gained the Rinnegan, but again when he died he didn't have them, Nagato did, and the eyes holding the Rinnegan have Izuna's DNA, not Madara's, so since he didn't have them when he died they were not a part of his body. Not to mention that Obito would have easily been able to store Madara's body somewhere only he could reach it, which would be important since part of the plan involved resurrecting Madara, which even the Rinnegan can't do without the body. So it's in fact very likely that the DNA Kabuto used was older, and that Madara still had his brother's eyes, Rinnegan or no, when the DNA was shed. After all, even if the body of the younger Madara was rebuilt without Hashirama's DNA, Kabuto probably injected it into him the moment he was summoned as part of the improvements, so there's no contradiction with him having the Rinnegan, since Madara still had all the knowledge he had about its use.

And this modification again doesn't contradict what I said. Madara was summoned, most likely in less than ideal condition, and Kabuto fixed him up. All I originally noted is that the fixing-process can't have been as short and simple as you implied here. You're right, a younger Chiyo may not be amazingly more competent, a but a younger Nagato WHO CAN WALK would definitely be. Nagato destroyed much of Konoha in a single blow, and with the power of all paths in his body would have been devasting, yet his potential was vastly crippled because the man HAD TO BE CARRIED in order to get anywhere. If modifying a corpse to come back at a younger age was as easy as thinking it while doing the summoning why didn't Kabuto do it to let Nagato move on his own rather than also bind Itachi, another formidable warrior, to lug him through the countryside?
I'm not saying the appearance of the summons CAN'T be modified, just that it would require more time and effort than you showed here.

Since you are not an immortal, you are hardly in a position to make such a statement. But the opposite is also true. Forever is a VERY long time, why WOULDN'T they want children at some point? Sure, the fifty-plus relationships Naruto will liekly end up with do take time and attention, but with forever to sort it out, eventually there will be a point where everything is known so well that there will be free time. Not to mention that unless you plan to pen all the girls into a single building, then the more girls there are, the less time Naruto will be able to spend with any one of them. There will be girls that won't have much of Naruto for weeks, even months at a time, so is there really a reason not to have a child to spend the time with? For humans, having a child is more than bringing forth the next generation. There's love, care, responisibility for the child, pride in watching it grow up and it's achievements. It is much more, and having a child with their true love is something many, male and female, wish for.

I noticed you didn't answer the question about the immortality's sexism. If say Tsunade gives birth to twins, a boy and a girl, and she loses her immortality, do both children get it? Because the daughter could then in turn lose her immortality when she gives birth, but the boy could literally sire hundreds of chilren and still be young, because unlike women a man doesn't have to want or even be aware of a pregnancy to become a father, so the son could not even know he's a dad. Or is the immortality biased the other way, only girls get immortality while the boys age normally even if they remain chaste their whole lives?
Also, if all this is decided solely by Kiyomi, how does she plan to keep track of all the descendants to know when she has to transfer immortalities? With twins and an eternity of time, the potential offspring having immortality will keep on increasing, becoming more and more difficult to overlook. Eventually she wouldn't have any time left for Naruto because she has to keep track of everyone.

You say it's selfish for immortals to sire mortal children and stay immortal? Why? Naruto's girls didn't ask for immortality, Kiyomi gave it to them. Not even gods decide as what they are born. More importantly, having the immortality go to the children in effect defeats the purpose of giving it to them. Kiyomi didn't give Naruto's girls immortality to create a race of immortals, she gave them immortality so that they could spend their life with the immortal Naruto as his lovers forever, the purpose of their immortality is that Naruto can spend eternity with them all. Unless you're planning on having the children born take their mother's place as Naruto's lovers, which would be pretty disturbing, there would be no point from Kiyomi's point to let a bunch of random strangers become immortal, she's not altruistic enough for that. Kiyomi wanted Naruto to not lose lovers, not create a lineage of immortals to play god for the unwashed masses.

Anyways, the issue isn't urgent, children are likely not going to come up in this story, or at least not until the very far future, so kinks of immortality and motherhood are not really important right now.

Yes, in a sense the number of loved ones isn't necessarily a factor of love, but one can argue against what Naruto does here, and to what extent it is all consensual. The problem isn't so much that Naruto has multiple lovers as the way he gained them. After all, he isn't going around the country looking for women that love him and then tie the knot, he's going out to girls who don't love or even know him and bind them to him. He's kind and caring yes, and a real loving relationship can develop from it, but that doesn't change the fact that many of the women didn't love Naruto when he recruited them, nor did he love them. Let's take Mabui for example. She didn't even know Naruto existed, and all Naruto knew when he met her is how she looked, that she was from Kumo, that she was in an important position, and that her diligent work would make it very difficult for him to do anything in Kumo as long as she wasn't working with him. That is incredibly shallow, and yet for the sake of Naruto's goal, however noble it may be, he basically tore Mabui out of her life and added her to his ranks, despite not knowing her at all. What she liked, disliked, favorite foods, favorite places, even personal background, Naruto knew none of the things that one expects the partner of the relationship to know. Mabui wasn't expecting a relationship with Naruto when he bound her either, she was horny, again Naruto's doing, and simply wanted a release for that. What happened to her had as much to do with love as a whale-catcher harpooning a whale. If there is any love in the situation it's toward the goal, not the being that is now a means to reach it.
Fact is that however the feelings may develop later on, Naruto seduces and tricks women into the bond with him, there is no love required for that to work. And in return, Naruto can't really say honestly that he loves all his girls. He cares for them, but he doesn't really know all that much about any of them, so he can't really love them in the sense that he knows and accepts all they are. That is in fact the root of the Anko-problem, despite claiming he loved her Naruto didn't understand Anko, and thus panicked in the situation he should have but didn't see coming. He just doesn't have the time he'd need to spend with each of his girls to develop deeper bonds with them, and instead of taking the time to develop real understanding love with the girls he has, he instead goes out to hunt for more.
There may be love that grows from Naruto's bonds with his women, but the founding reason for what Naruto does is not love towards the women he ensnares, it is his selfishness to do what he feels he must to reach HIS goal, he is sacrificing the true and unbiased free will of his women for his goals. Yes he leaves them with a measure of freedom, but that is after the bond has been made, very few girls were given the information and then freely decided they wanted to be bound, most had the option made available only after the act was done. Even the filler-girls you mentioned, their emotions are more akin to admiration, they have crushes on Naruto, but they simply don't know him enough to truly say that they love Naruto, because they only saw him for a short amount of time and in very specific situations. One can argue how much of Naruto's relationships is built on lust rather than love.

Point is, there is a degree of selfishness in Naruto's actions. He himself acknowledges this during the recruitment of Pakura, when he doesn't recruit someone who is very receptive, almost dependant, on his touch for the sole reason that she's not useful to his plans. He feels terrible about it, but he none the less acknowledges that he is selfish in that aspect as he meddles with the lives of women, and in a sense the possible love-partners they might have had. After all, the kunoichi he didn't take will now likely spend the rest of her life thinking back to that 'ghost', comparing all her future lovers with him and feeling frustrated when they fall short. Naruto is not a completely selfless person. He isn't evil or malevolent, but like all humans he is selfish to a certain extent, and that selfishness is one factor that influences his decisions.