I thought I would field this one, after talking it over with Dot. :)
The Unions are less like overarching governments and more like the current European Union. Each constituent country makes its own decisions for local government and policy, but each country either agreed or was compelled to enter the Union for demon defense purposes. For example, large amounts of both financial and natural resources are required to fight this war and the Unions allow for these resources to be taken and distributed to local ADAMS defense centers. Having the Unions also makes it so that Union troops can cross country boundaries to intercept demon attacks without needing additional clearance.
There are probably tons of localized policy arguments, particularly when a country's economy is suffering due to ADAMS taxation and resource usage, but our story doesn't really focus on that. You can feel free to add it to your character's background, but it won't be a part of the main plot. In that sense, go nuts with political speculation. :) We'll let you know if anything conflicts with the feel of the world.
As for technology, the level is certainly advanced but not to the level of high science fiction. There are probably lasers and plasma cannons, but the feel is overall more industrial. Prosthetics and the like do exist, even enhanced versions. But these prosthetics tend to be expensive, sometimes prohibitively so. For that reason, many enhanced prosthetics are mostly used by military.
In general, most of the technology is impressive by our standards, but it was made in a desperate, war-ravaged economy. It will have scifi functions but it may not look particularly pretty, have an acceptable success rate, or even be safe. Most weapons will get pushed through development out of necessity.