Seems like an interesting idea, I'll try to help if I can.
1. In my mind, you should definitely have a set story and goal, un structured roleplays always seem to end badly in my opinion. However, accept what others may do to slightly modify that story. If somebody does something that you think may alter the overall outcome of the story, just go with it. Don't find yourself controlling every outcome, because at that point it becomes less of a roleplay and more of a book. I would watch out for anything that may greatly alter the story though. Say, you are at a space port and you want the members of your party to get on a ship so that you can begin the main bit of the story. If somebody says "Bob, being slightly drunk, accidentally pulls the release lever for the ship, dumping it into space." Here is the point where you should step in and point the party back in the right direction.
2. I also prefer to structure my CC's this way. It makes for interesting conversation between characters and generally can make the whole experience much more interesting. I think the adding to their character charts over time is a great idea, and allows people to look back on in case they forget.
3. This one is really up to the GM, It's always good to allow people to have their silly moments once in a while, it keeps the RP fun. Don't let things get out of control though. I recommend looking through some of the fun RP posts, and try to make yours as opposite of their structure as possible (to an extent of course).
4.This really ties in with 1, keep the party pointed in the right direction, but try to keep the RP from turning into a book.
5. This, is important. For the reason of if somebody is away for a while, especially in the middle of a conversation, it can get very awkward when they return. If somebody says that they are not going to be able to post for a day or two, then that's fine. just be patient and if they really want to be a part of the RP, they will keep their promise. If they don't however, or if somebody just stops posting in the RP, try sending them a message. If they still don't respond, now you skip them.