2) Linked in with the above, assuming it is an RPG, how do you write regular scenarios and keep them from just being a "storm the target and shoot it up" setting each time (no insult intended) ?
Because the TW:2k's basic premise is that the game begins when that stage finally comes to an end for your players. Civilization has disintegrated, the old order (the world as we knew it) has been mostly irrelevant and is become more irrelevant all the time. The players were part of a loyal, functioning (if at a much lower level) military unit. But even they were aware that being part of the "United States military" was becoming increasingly irrelevant. The other side is experiencing the same problems.
As the war basically ends in the timeline (at least for the players), they suddenly look around and realize that Europe has changed. There's city-states arising out of the old nation states. Things are looking decidedly medieval in many ways (as a TNE player, I'm sure you'll have a decided feeling of "hey waitaminnit when have I seen this before?" when reading through the 2k setting materials - TNE is basically the lovechild of TW2K and Third Imperium Traveller). What the players do at that point is up to them. Some seek to go home, some seek to stay in Europe and make a new life for themselves (of some sort), I had one group of players who literally wanted to play Marco Polo! One of them as a college history professor before he voluntarily joined the US Army (better than being drafted he figured) and became a staff officer. Because of his background he realized that in the future, a "primary source" memoir of the world right after the end of the Twilight War would be invaluable to future generations. The other guys in their small unit agreed and instead of heading west out of Poland, they headed east with the intention of getting to Alaska and getting home that way.
3) Also, is it written only from a US PC perspective, or are other nationalities supported? I am toying with a Russian perspective, hence the question.
In the original version (which I believe is the best), there's a very heavy bias in the setting lore and details towards a US perspective. Eastern bloc types seem to disproportionately represented in the "pitiless warlords", "souless marauders", and "brutal mercenaries" categories (it's not all eastern bloc types, but it feels like 80% of them are).
The basic chargen and so on pretty much assumes a US military bent; there's some rules to cover other NATO nations and eastern bloc nations, but again, there's more detail for the US. There's greater detail for the other nations in later editions but the later editions never seemed to last as long and didn't have the history of player written articles in Challenge and so on which made TW2K such a joy to play; having an actual Abrams tanker describe the kind of equipment and the reality of the Abrams tank ('yeah the .50 caliber can be fired from the inside of the tank, as described, but it's actually fired with this chain thing and it's not accurate at all') was a great help.
You can play as other nations, but there's decidedly less detail about them. One of the most fun things in TW2K was to play with actual military members - they're able to really give the game a lot of "feel" that the rules, equipment lists, and so on lack - like filling in the details about the difference between the TO&E on paper and what would really exist in a military, small details like what actually consists of a infantryman's field load, or what's really in a personal medkit (depressingly little), and so on.