I was more or less waiting for another member to post here before I gave you a second response, in order to avoid creating a single post that was really long; even if it's rather nonsensical considering this is a site for [i]writing[/i] and people should learn how to read if they're going to involve themselves in play-by-post (as I was insinuating in my first post), but c'est la vie.

Most of my comments in the initial post were in direct response to the title of this thread (which I considered the primary question due to it being the title). Now that I've given you my thoughts on "stagnant ideas", but give you a little bit of an idea of my thoughts on the question at the end of your post. I would've in the previous post, but "walls of text" are bad apparently (a lot of role-players must [i]hate[/i] reading novels). I've got a lot going on right now and I need to get back to it, so I plan on keeping this shorter than I usually would.

I'm going into only three aspects of writing in this post, and only touching on them a little. For the sake of ease of use, I'm putting my thoughts into point form, so here goes:

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[*] [b]Project Size:[/b] If the story you have in mind is simplistic or easy to work with, you'll usually be able to solve most of your problems just by breaking up the ideas into smaller questions and finding solutions to them. Simplification works wonders with a simplistic story. However, if the project is a lot bigger (like my main one is) then this sort of thing will become less useful since you'll need to manage a lot more information. I suggest creating a database or "wikia" if you intend to work with a much larger project, and make sure that you have notes categorized by topics.

Depending on how big the story you have in mind is, you might also want to invest in creating a timeline as I have, especially if the story you have in mind involves as complex backstory and history involving multiple characters. I actually make a point of dating every single chapter of my story (using the same method I do in my bio) at the beginning in order to show exactly where everything happens. This prevents jigsaw puzzle problems and makes it easier for readers to understand and piece together my story. Having a timeline makes it very easy to use this dating system, though that sort of system is not needed with a more simplistic story, but based on your initial post it sounds like you want to be complicated (which is a great thing, if done well).
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[*] [b]The Details:[/b] I'll say this again, even though many people don't like how detailed I can get in discussions, writing a well thought out story is [i]entirely[/i] in the details no different to how giving a successful debate is about scrutinizing the details. You need to question every facet of your project and every detail of the setting in order to make things more fleshed out. When I work on a project, every single character is fleshed out in vivid detail (no matter how minor they are) and every element of the world is detailed and thorough. I find the biggest problem that people have when it comes to writing a compelling story without any plot holes (a trap that [i]many[/i] writers fall into) is that they focus too much on building just the story and not enough time building the characters, concepts, and setting itself.

I actually spend a fair bit of time supporting other writers by pointing out plot holes and contradictions that they failed to see, and I can tell you that in [i]every[/i] case the problems came up as a result of them missing details and not being thorough enough with questions regarding the characters or setting, not so much the narrative itself. A large number of works of fiction, even some of the most highly renowned, actually carry notable plot holes that the readers usually just choose to ignore or don't notice (some of those who do notice them parody them on the internet), but all of these contradictions could be avoided if the details had been not only questioned but fleshed out more thoroughly to create a more realistic work.
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[*] [b]Objectivity and Subjectivity:[/b] This may seem like a weird topic to bring up, but a lot of writers, especially those who are role-players and not writers outside of that (you need to be a writer to be a successful GM, not just a role-player), but understanding how to write from the perspective of the world as a whole and understanding how to write from the perspective of a specific character are both important skills to creating stories, and neither can succeed independent of the other.

Most role-players are used to writing from a single perspective in a story, which by its very definition is only one set of eyes out of billions. Learning to see the story from the eyes of every character, including the eyes of characters who could be introduced through people joining your role-play, is important. Due to this, having an objective understanding of your entire world and setting that doesn't centre around one character's perspective is useful, which is one of the reasons why I suggest that people focus more on building their world rather than simply writing the story.[/list]