Generally, I don't ask people what the next plot development should be. A good story has a sort of overarching path to it. You know the beginning, the end, and the points in between that you have to hit in order to make it work. I imagine that your method will make it very difficult to do such things as foreshadowing.
Then again, I write a very different kind of fanfic than you do.
Don't take this as discouragement. If you can manage to write a good story while everybody is dictating its twists and turns—sometimes for reasons that are less than mature—I'll be really impressed. I'm just warning you that there are risks. You may end up working even harder than I do on my fanfics.
One last note: keep all your verbs in the same tense. And distinguish between "effect" and "affect."
And make Joe go on a date!
