Hi Trinity,
I will try to answer some of your questions.
I remember that my daughter Yiren started writing long research paper when she was in 5th grade (10 years old). She was in a self-contain GATE class. The highlight of the curriculum is four Historical Pursuit Projects in which they need to select a topic in the time-period, write a one page short summary, one long essay (5 page single space), make a 3-D model and do an oral presentation.
Like your son, Yiren loved some strange topics. For example, her first HPP topic was "Suleyman the Magnificent and Ottoman Architecture". You can read it with this URL
http://www.employees.org/~clu/Yiren/Suleyman.html
We just borrowed some books and did some Internet research. Somehow she was able to put all the material in her own words and construct a pretty decent paper. Teacher did not teach them about how to do research paper but he did provide a list of possible topics. Of course, most of which are not as off-beat as the "Suleyman" or "Religious significance of the Nile". Although most students were able to meet teacher length standard, the quality of writing varies wildly.
I think that Yiren started to cite sources in 6th grade (not for class but for some competitions). It requires a little bit training. But just give them an example; they will be able to follow the rules.
Kids will be happier if they are writing something that they are interested in. If they are truly not interested in a certain topic, there is little point to force them into doing it. However, when they get older, they will realize that the curriculum was not designed around their interests. Sometimes they just have to work on it.
In my opinion, "summarizing and integrating the source material" is the first step of a research paper. "Pursuing a question using source material" is one level above. It requires using material selectively to support his own position.
My daughters were very lucky being challenged like this when they were in 4th and 5th grade. They learned a great deal from these projects. These types of research papers were not required in most middle schools until probably 8th grade. If the teacher requires kids to write research paper when they are 10, count yourself lucky. Do push your kids hard to write more than required, to go more in-depth, etc. Some kids know that they will get A if they write one page plus 2 lines so they stop at one page and 3 lines. Don't let him do that.
I hope this helps a bit.
