6) Will there be a grace period for assigned posts?
Yes, you will have a grace period.
I am going to show a vague set up of the first couple levels of chaos to come and ask for volunteers. After that, I will set up a schedule and random assignments similar to Nnoitra's with one big difference. The due date will be a bubble of two to three days, depending on how detailed or complex the part is, giving the RPer time to do the post right, even if something happens to distract him in RL.
Note: If I get a message in advance that he can't do it, I'll adjust without making a penalty.