Main Plot and Quests

Hello everyone. After experiencing many roleplays on this site, I've noticed that one of the most frustrating things is that roleplayers can often get stuck and "not know what to do".
Thats why I've incorporated a "Quest System" in this roleplay. Each character will be assigned tasks and encounter various obstacles throughout the story. As an example, in the beginning of the story I've asked Derrick Maple to go and interview the family of a missing child. At this point Derrick can take full charge of this quest, has full autonomy and can write how things turned out. Also note that you don't have to wait for me to tell you what to do. You can assign yourselves quests, make up your own side characters, etc. Be creative and find something to do. Just a couple points to keep in mind:

1) Although we don't have an exact set "Ending", we can agree on a main plot and write our posts accordingly. So the main plot is this:
a) We don't really know if Slender Man really exists. He could just be figment of our collective imagination.
b) If Slender Man is real, The mystery is whether or not the people he kidnaps are still alive or not. If they are, where does he keep them?
c) Perhaps Slender has some sort of weakness???
d) What are the reasons why Slender is so interested in this town?

2) Your character should encounter difficulties and trials. These are important because it shows your character's personality.

3) Make up your own side characters and places that are related to the main plot. Some examples might be people who know a thing or two about Slender, certain objects or places that might be related to Slender, or people who can give you clues on where to go and who to talk to.