With the fiber optics, you need additional I/O elements that will convert electric - digital signal, to light, and vice versa. It is not faster, at best the speed is the same, the only difference is lack of interference along the way - that's why optics are used in hi-end music systems.
The FBW system may be easily shielded against EMP, all you have to do is feed flight data to it by fiber optics, and give it's own backup power supply, that will work if the main one get fried. Anyway, the F-16 was designed when nuclear warfare was widely considered, so I believe, those issues were worked out long time ago.
The beauty of FBW in contrary to the push rods in military aplications is - you can do 2 or more wire lines that will weight as much as 1 push rod system. therefore if one line goes out due to combat related demage, you still have the second. You don't have two sets of push rods in helicopters - it goes out, and you're just a passanger.