This idea you have is one I've tossed around for many years; on so many levels. You appear to desire a small number of people in the company. I've toyed with a company of ~100 or more; a battalion of 500 - 800 or even a Brigade sized organization of a few thousand. Starting with just a handful might make it simpler, to at least create and learn a system. I applaud your efforts and would be willing to assist you in the creation process if needed. How much detail do you want to put into the world? I can help with world creation if you like. I see 6 nations, listed below and their cities.
	
1. Kingdom of Raxas
[list]* Raxas Castle
* Arcot
* Seton
* Windhir
* Hargrove
* Reford
* Eaton[/list]

2. Kingdom of Karnoras

3. Republic of Praeda

4. Kingdom of Lotheloni

5. Kingdom of Bapha

6. Dominion of Malaph Kar

[b][i]Innish Sea[/i][/b]
[i][b]Sea of Omens[/b][/i]


I am willing to help you build this world. If you employ the aid of those willing to participate in the creation of the world, encompassed within your vision of course, you create a sense of ownership  amongst the participants. They are less likely to jump ship due to any investment they make into the design of the world itself. But this should be on a volunteer basis. I would not want to impose any additional responsibility upon someone who may not desire or be capable.