Not jobs actually but restrictions that people can't steel stuff from a group or edit map so that other members aren't happy about it.
So say a person who started a pack is designated leader, he can edit maps, invite new players and is in control of everything.
He makes some of his pack officers and they can do most of the stuff he can with maybe one or two exceptions (maybe not editing maps)
Now a new member maybe can't do anything in the pack except enter the pack map. They can later be ranked higher with more privileges when the starting members know them better and trust them.
...You're essentially repeating what Haruki said in different words. That /is/ designating jobs. Also, I /highly/ doubt anyone but the original map creator will be able to edit it, which by the way, who says its going to be the leader in every case? I made maps for groups all of the time that I wasn't even /part/ of. Honestly there is /no/ need to put hours of work and code that you could easily designate yourself and say "Joe shmoe, this is your job. Do it." If you're paranoid about "lower" or "newer" members reaching out to do anything past being a newbie in the group, you're taking the wrong approach entirely. "Goodness forbid, Johnny went above and beyond his 'rank'!" Like... seriously?
Odds are, [assuming you are a kid/teenager, or even if you aren't] you're most likely going to be RPing with other kids (likewise, the adults tend to bunch together into their own little community and RP with each other) and every one of them is going to want a piece of the pie. That's life.
Also, actually making an ORGANIZED neat thread on the forum and working to attract the right kind of people and kicking out the wrong kind /does/ work. The two longest lasting Role-plays on the game are Pyrrhic Passion (which is about a year old now) and Archaic Revision, and hm, what do you notice? They both have organized threads. You don't need an in-game system to organize yourself and your group. I've been playing games in the Impressive Title series since 2008, and this is consistent everywhere. The ones who frequently look over, update, bump, and organize their threads in a neat fashion are typically the ones with the roleplays that don't abruptly die off. Those who have in-game systems, or try to "advertise" (cough, spamming their group title cough) don't last more than a week, tops. You don't need an in-game system because as I've clearly already said it does /not/ work. You can take my word for it, or choose to ignore me but everywhere I've been, people with well kept, organized threads that keep track of their members outside the game do far better with their roleplays.
Also, what are you afraid of people stealing? Names aren't copyrighted, neither are ideas for roleplay, so I don't really know what you're scared of people taking from you, especially when the above doesn't belong to you in the first place. You can't "own" any of that.