Is "interesting read" a valid reason to bump? I'm just wondering.
I think people are misunderstanding (or, did three years ago, anyway XD) about Chibi-Usa's need to be "raised". While she is still somewhat of a child at heart, she's also over 900 years old, and in a world where 1000 is the general life expectancy, there's not that much "raising" left to do. I think Neo Queen Serenity was crediting Small Lady with a certain level of autonomy necessary for her in her condition. Chibi-Usa is a lot more like a teenager, and a lot more like one of Usagi's peers, than just a little child. Her appearance easily throws people off on that, and she does behave a little like a child here and there because that's what she's been used for for about 900 years. The 20th century is the BEST place for her to grow up and mature fully for several reasons.
1. Crystal Tokyo is at peace for the majority of the time. Wise Man has been their only major conflict in an entire millennium. This means that to train as a Sailor Senshi (in the event that Sailor Senshi become necessary again), she needs to be at "ground zero", so to speak. Also, there is extreme value in experiencing pre-Crystal Tokyo history. To understand her present (CT), she needs to understand the past (20th cent), and what better way to do that than to be there?
2. The Legendary Silver Crystal operates through maturity of the heart and bonding with close friends. Since, as I said before, it is unlikely that Small Lady could do much training as a Sailor Senshi in Crystal Tokyo, it makes the most sense for that to happen in the past with Sailor Moon and the other Sailor Senshi during the upswing and peak of their powers. Remember that NQS can no longer transform into Sailor Moon, so probably the most important factor in play here is the presence of Sailor Moon herself. Sailor Chibi Moon helps provide power to the other Senshi as they help provide power to her. It is the natural order of the Silver Crystal and the nature of Sailor Senshi in general.
3. Chibi-Usa had already hypnotized Ikuko and the rest into accepting her as a family member. Not only does that mean that Ikuko and Kenji are raising her more than Usagi is, but her absence would critically impact the family. They don't know she isn't actually her daughter, so what happened to her? Did she die? Was she kidnapped? They'll take her information to the police, and then all sorts of havoc will ensue. There's no birth certificate, no photos or records of her birth up to her apparent age, and lots of other legal and practical information is missing. The family would be broken in her absence.
4. Usagi doesn't raise Chibi-Usa. Period. She's not responsible for her education, rewards/ punishment for behavior, scheduling appointments, enrolling her in school, etc. They're effectively sisters here, but NQS didn't send her back to be "raised" by Usagi.
5. The thing about Chibi-Usa causing "interferences" in Usagi and Mamoru's relationships are minor. In the first place, ANYBODY can "get between them" at the same level as Chibi-Usa just by being insensitive from time to time. In fact, the people who interfered with their relationship the most were the likes of Galaxia and other enemies who were intent on destroying them or controlling them through their power. But the key about the Usagi x Mamoru relationship being disrupted at any time by Chibi-Usa was attributed as one of Usagi's weaknesses. Chibi-Usa can't get between her and Mamoru without Usagi's consent. Usagi was letting herself feel jealous and protective of her relationship, but Mamoru tended to take it all in stride, acting maturely the whole time. HE never felt like their relationship was ever threatened; that point of view was Usagi's alone.
6. Life isn't fair. Most especially life is not fair to a Sailor Senshi. That's established several times throughout the series. Their lives will simply never be 100% under their control, because there will always be opposing forces intending to disrupt their intentions. So, is it unfair for Neo Queen Serenity to send Chibi-Usa into the past so much? That doesn't depend on whether or not the individuals in question are able to "feel like teenagers" and have fun. Those are selfish motivations. What is important is whether everyone involved experiences positive growth-- which they undoubtedly have.
And anyway, I see the girls hanging out in Tokyo all the time, having snacks at the Fruits Parlor, playing video games in Crown Arcade, watching Michiru and Haruka and even the Three Lights perform in a concert, struggling with their entrance exams in school, etc. I see no evidence that their lives as teenagers has been significantly disrupted. Sure, they have more responsibilities, but the "teenager experience" is a wildly diverse scene from culture to culture, or even within a single culture. There are teenagers who finish college early and start a home business or work on a farm as young as Usagi and the rest. There are teenagers who have nearly their entire lives robbed from them through murder, drugs, violent crimes, severe medical conditions, or other tragedies early in their childhood-- they are forced to grow up much faster and harder than Usagi & co have to. And in some cultures, teenagers simply don't have the same experiences across the board. Some cultures expect teenagers to be far more mature than the US tends to be, and are given more responsibilities. And, if you still want to debate the fact of "raising children" (which as I said, I see no reason to believe Usagi is at any point "raising" Chibi-Usa), there are cultures and religions which encourage that at their age, and sometimes it's simply encouraged within the family.
The fact is, just having some more responsibilities doesn't take away from people-- it adds to them. It is what makes them stronger.
So when you really look at it, Usagi has a pretty normal life-- she just ALSO happens to be a superhero with a few extra responsibilities. Life was already that way before Chibi-Usa showed up. I see no reason to believe Chibi-Usa's presence is in any way "unfair" to anybody.