Thanks for your answers R@S !
I indeed figured out most of what was bothering me. I understand that there's no banking system in 7.62, what a shame.
As for the mod and the weapons, I think they are great and I do not miss the Tactical flashlight a bit.
I seem to have one problem and I know it has been posted somewhere else on the board: When I take a city, the Gvt takes it right back. I don't even suceed in raising troops for the militia.
Should I talk to the "locals" ?
Also, I have the mission with the mechanic who had his family killed by Thugs from Santa Maria. I already killed one of them, but I can't seem to find the others, it is like they have disapeared from all the other cities.
EDIT: OK I figured out how to raise militia, and the militia system is not very ergonomic if I may say so. I don't understand the Budget mechanism, where does the money come from ? It doesn't seem to draw funds from my account, so what is the goal of the budget ceiling ? Is there a limit to the number of militia I can train in a given city, and also can they take a city without my help ?
I've completed the Mechanic mission by asking the right guys and with a bit of luck

Also I found the book of Koans completely by chance. It is well hidden to say the least.