Completing 100 % in GTA 4 is bit difficult. Though there aren't as many missions in GTA 4 as it were in San Andreas, the missions are good. Make sure you have met many side missions on the road.
They are marked with a green symbol or so. You may get lots of them and the characters request your help. The characters spawn randomly throughout the map, and so you need to surf around the city and some one might just pop up on the map seeking your help.It could be killing someone,spying around, trafficking drugs in a car, or helping him fight someone.
Better leave the stats, and since you have completed the main story line be satisfied with it.
Here's a checklist of all the missions in GTA4, story and side stuff, so you can go through and see what you did and didn't do: gta4.tv/100percent.php.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.