I would argue Civ4 is still a wargame. Scoring fundamentally favors early conquest and domination victories. Rapid expansion, although slightly penalized by the maintenance factors, is still the best strategy irregardless of which victory you are pursuing. So long as your economy can turn a profit at 0-20%, you are fine (use the library-scientist to pump your research in the meantime).
What people freak out about is the slider. When they see the sliders fall to 40% science, they start freaking out. What people tend to forget is that 40% of 100 commerce is greater than 70% of 50.
I don't think we're disagreeing. I agree Civ4 is still a wargame and does favor early conquest and domination. I'm a Civ4 warmonger who likes the early rush. However, Civ3 was even more of a wargame. It's true that some people worry too much about the slider in 4, but you can never crash your economy in III except by underexpanding.
40% of 100 is much better than 70% of 50 because later in the game your edge will be that much more.