One thing that has always bugged me about NS, (as much as I like it) is how incredibly fast the population growth is and how quickly nations reach over a billion people.
It's not a terribly big issue, but it does have certain disadvantages. I think it might be discouraging to new players who would like to RP with nations that may even be only a few months older and may make the larger nations harder to manage.
Many players simply RP with a different population than their profile suggests to avoid this, but that can have problems of its own.
So my suggestion is that everyone starts with 10 million people or so and grow by 1 million per day. Whether or not this change should be retroactive or not (For example by cutting a zero off the populations of current users) I don't know, it certainly would not be popular with everyone if put into effect.
IDK, just something that crossed my mind.