I totally agree with you on your POVs regarding immortality. It will not do the world any good if people can be immortal at the same time have children.
Yet given the options, I wonder what each of the women would choose. Ino, Konan, and I'm sure some others wouldn't mind being immortal to stay with Naruto. However, would some of them want to become mothers? If yes, would Naruto age with them if they want him to father their children? Hinata is likely one example given she is the heir of her clan, so if she wants to become the head, she would likely need to have children. Then again, being immortal, she could rule her clan forever. :)
So even though they would not need to think about it now, when everthing is finished with uniting the world, they still need to think of who would want to be immortal and who not. To mention, you have not bother to touch whether Naruto would regain his immortality if some of the women want him to father their children.
(sigh) Are you going to bring Mito to 'life' as done with Haku? It would become cliche to use this technique to keep bringing women back from the dead. Maybe it would be okay to have Naruto have a fling before they return to Heaven.
Anyway, I'm looking forward to what will happen with Mito. It would be quite interesting when Naruto romps with her. XD