I have been in the Detective Conan scene for like 7 years now? There has never been a dedicated faction in the Detective Conan fandom serious about roleplaying that hasn't died in a month or two. Also, LucasIchiro, there is even less interest in "elite" roleplay like you are describing vs causal pickmeups. Ain't nobody got time for that. I think there are several reasons why:
1) That's just the way the DC fandom is. Here we get maybe 15-30 unique people posting per day. At DCTP they get a few more, but not a whole lot. It is relaxed, without the hopping activity that roleplay-friendly fandoms have. I do not see those numbers going up in the next five years. Detective Conan passed its sort-of-spike in popularity now that the people who remember watching the show as kids have come and gone and the efforts to air the show in English have been exhausted.
2) Also, while I might be wrong, I am under the impression that roleplayers tend to be young rather than older. DC in my experience is older demographically than say the fans of Naruto or Ranma 1/2 back in its heydey. It also has a lot of English-speaking not-Anglospherians who aren't as interested in roleplay.
3) The characters are hard to roleplay. DC is long, and you have to know a lot to get the characters right. The backgrounds of many characters, protagonist and antagonist, are mysterious and not many people are willing to plunge off into the unknown. It's the same reason why it is incredibly rare for any fanfiction to show up about arc characters before their arcs are completely done.
4) Other types of forum games appeal more to the average DC reader. It don't think it was unexpected that Mafia, a puzzle-type community game, took off in the DC fandom at its peak of popularity. It is a better fit for the fandom who like the mysteries and plot more and the characters second for the most part.
In conclusion, LucasIchiro, I think you are better off trying to start a DC roleplay at one of your "elite" roleplay sites than here. Crosspost here about it if you have something and maybe you'll pick up a few participants. Here, there are not enough people who care enough to meet your high standards.