spy and photo missions question

[Joe S]

I have been ordered to insert an agent, which I did, and was looking forward to sinking some ships on the way home, which I did, but then I made the mistake of radioing my status and I was ordered to go back and photograph a harbor. I assume that I am to avoid enemy contact until the mission is complete but that I am free to engage enemy shipping on the way home, True? I am a little bit concerned about having enough fuel to go back to the mainland and then make it home. How can I find out if I have enough fuel? I have a little more than half a tank which I think should be enough but I am not sure.
After I sucessfully landed the agent on enemy shores, I assumed I was free to sink enemy ships on the way home. However, this second assignment is different. If i dont make it home with the camera and the film, I have compromised the mission. What are the rules of engagement for the return trip from a photo recon mission? does the "game" really care?Thanks! Joe S