Pre-Pitch: Occupied Territory

I'm starting to figure out what the campaign will be. I still am researching the concept, but I wanted to get some basic points down for you to comment on. My main concern is having something "unrealistic", even though it is an alternate history story. For example, I know that it would be ridiculous to think that SF may be occupied by Japan, but Oakland will be under US control. Below are my ideas:

• The campaign will take place in San Francisco around 1942/42. Japan has successfully invaded Hawaii, several other Pacific Islands, and the San Francisco bay area. I'm not sure to what extent, but I think that is as far as Japan will have progressed when the campaign starts. There will be a line where the US and Japan will keep fighting for superiority.
• Of course, with SF being under Japanese control, the town will be under martial law. I'm not sure what that means yet, but I think it will allow me to focus on keeping the game locally. That isn't to say that you cannot find your way to a different part of the world, but it won't be easy as taking the next outbound train.
• I'm guessing your character will be an ordinary citizen. I'm not sure if they will have their old job, or if they will be forced to work for the war machine. In either case, you will not be military (unless you're undercover...)

Anyway, let me know what you think, good or bad.