I don't know much about NRP, only been in two here on the forum before I stopped participating. (Actually it was one, but it had two parts.) - It is basically just what it says - it is more about the Nations overall than the characters. (Granted there are more character driven RP's.)
Basic break down is you create a nation using a sheet like a character sheet but you go more into the demographics, populations, politics, religions, resources, and more. You work with others to plot out schemes, over throw other governments, take over territories. It's like the board game RISK, just in type form. It's a lot more complex than that of course but that is just an overview. It can be a lot of fun, loads. It to me though just takes a certain type of RPer to enjoy it.
Rpers like @Monkeypants, @Isotope and others in the NRP section could give you a much better idea.
Eh, not as much as you'd think. Many NRPs actually function without a reliance on stats and the like, and without an emphasis on winning like a game like you've described. There are elements like demographics and GDP and whatever in play but it plays less like "I have 2000 tanks and he has 1000 so he's overthrown" but more of a way to set the story.
The way I view them is that they're bigger scale RPs where you display larger national concepts through your story. Take, for example, Precipice of War where I've been playing Armenia for about four years now. The characters are characters with their own stuff (a military policeman who wants to get out and become a musician, a gangster trafficking drugs to support his family, a president who's overworked and trying to protect his revolution's legacy, etc.) which would be similar to a regular RP except maybe with one guy playing more than one character... But deeper in it, it's not just a story about a military policeman detaining refugees illegally crossing the border, it's a story about the interplay between politics, ethnicity, economics, war, and everything else.
The characters are less the story themselves and more the vehicle for the story, if that makes sense. That's what I feel like the main difference is.
TLDR it's not a regular RP and it's not a stats/tabletop RP either. It's some sort of weird mix.
