There are some technologies that you would need, or wouldn't need.
Personally, I focus on tech that relates to improving income, so upgrading school, Inns etc. Also, tech for your armies would be good as well, so you can improve within battle. But really, try and go for income, playing as France is pretty hefty when you're pretty much by yourself so you tend to use most of your money on new units and to upgrade military barracks. Taking other regions and upgrading farms can also help with income, however, taking regions is better as you get more income after you've ended your turn.
That's all I got really, if it helps great, if not then I can see if I can think of something else that may possibly work.