I wouldn't use the tax option since it really pisses the cities off. Yeah, make Paris and a few other interior cities that you don't need to defend be supply bases and don't worry if they starve. There's also an option to toggle food sufficiency between low and high and I always make it low. Fuck em
I'm not sure about the recruits. It must be a factor of population and a few other things relating to general happiness of the city (e.g. food sufficiency).
I typically start by making alliances immediately with Spain and Turkey if possible, rolling up the Scandinavian countries, then Prussia, then Austria, then Russia. Once is Russia is gone, it's all downhill as you work on Turkey, then Spain, then finally Britain (which will be starving and in poor shape after they can't import from Russia anymore). This is for scenario 4, however. I'm sure it's a lot tougher starting on 1.