Suggestion-Jobs

How about when you become a rank you can sign up for a job and get more money, justu and new items.
like for Anbu, you must be a Jounin. When you become one you get Anbu Attack Gear and some rare Fuuin and Gen justu.

And for Medical Nin, you must be a Chuunin. When you become one you get Medical Dress and some Powerful Healing Justu.

I made this last one up... Akatsuki, you must be a Missing Nin and PKed 20 people. When you become one you get Cloak, Ring and Hat but theres no pay and your a wanted ninja.

I'm pretty sure we've already got entry into Akatsuki planned out but apart from that nice suggestion. I agree with the Chuunin requirement for medical and also with the Jounin requirement for Anbu. As for missing nins i've been thinking that missing nin players can have their own missing ninja clans so maybe the pk count can be used as requirements to join those.