Let's see what I can come up with...
It seems you have a lot of your idea fleshed out, but a timeline of key events could help. Just take some of the bigger events, and write out who is involved, what happens, and what the goal of the scene is. The more you know about the scene, the easier it will be to write out.
Also, a map of the area would help with keeping yourself oriented and with time spacing, so drawing down where your fic takes place on a piece of grid paper can go a long way. If your fic takes place in several different areas, then go ahead and draw a map for each area so you can really nail the details down.
The point I'm trying to get at is that the more details you have fleshed and thought out, the easier the story will be able to write, and the final product will probably be better. It sounds like you have a pretty good start on that, so I won't bother you with too many ideas. Although, giving some thought to the relationships each of the characters have with each other will really help with consistent characters, and character growth.
I like to plan out each and every detail I can think of, but that's something a lot of writers don't do. If you feel like you're ready, then go ahead and start writing! You may find that you needed to plan more, or that you thought too much of the story out, and you make adjustments for your next story. It's all a learning process.