1) A few tweaks to the code and database table(s), you'll sure have a working system.
2) There is a level system on here, where you have to click the button to upgrade. I'm pretty sure it's in the free section, if not I have it somewhere on a old hard drive laying around that I could send to you. A few tweaks to the code to integrate your missions/challenge system should have a pretty decent system going.
3) I need more explanation as to what you want doing, I'm sure others will want that too, or I'm just dumb today and don't understand what you're saying.
4) Oh right, hit me up somewhere, I'll give you a hand if wanted.
And CrazyT was my old nickname, just don't remember the e-mail address used with that account and/or password. It's been way to long (: