Grunthex's brilliant story (on another thread) is quite instructive on the merits of the trade off between expansion, development(i.e. build wonders) and warfare.
At present I'm willing to bet that it's a struggle to try and do all three. You can expand and build an army, or expnad and develop, or develop and build an army. But, trying to do all three would probably leave you seriously disadvantaged in one or the other.
This is very different from civ IV, where it was quite feasable to rush a neighbour in the first 100 turns and knock a wonder out, and then develop quite quickly as a result (by getting code of laws or metal casting via oracle). As such, I suspect the first 50 turns can't be conducted without reference to your starting position...
Aggressive neighbours focusing on miltary techs that didn't expand too quickly would have an advantage in troops size and composition over a nation that had expanded aggresively after building wonders then neglected military techs.
As such, the first 50 turns will set the gameplay for the next 100. If you develop and rex, don't try to go on the warpath until much, much later on.
I also need to eat humble pie here. Trying to Rex with the French would be a bad idea and would negate their cultural adavantage. Adopting tradition, aristocracy, building stonehenge then filling the honour tree is likely to be the better tactic.
