geostationary is pointless for a recon sat (unless its a weather bird) as you can only take a picture of a limited area. so unless you want to look at a particular area constantly for a long time, most of the sorts,of assets that would be useful would be non geostationary.
Maybe. All I can tell you is the US launches a lot of highly classified satellites from Vandenberg AFB, California directly to the south. Those go into polar orbits as you describe, and as the earth rotates underneath them, they are able to "mow the lawn" every 24 hours.
We use that location because there is only ocean south of Vandenberg for 1000's of miles, so if the booster fails, their is a low probability of damage to anything on the surface.
We also send up a lot of highly classified birds out of Cape Kennedy, Florida. There are 2 reasons to use Kennedy. First, you've got about 1000mph of speed because of the earth's rotation, and that saves a lot of fuel. The other reason is that it's the most efficient base we have from which to launch satellites into geostationary orbit. Geostationary orbits have to be about 25,000 miles above the planet, far higher than the polar orbit birds launched out of Vandenberg.
Geostationary does not mean it cannot be moved and parked over a specific area. It can, depending on what you want to look at. But it does have to be near the equator. South or north of the equator the angle of view becomes more oblique, and the light passes though more atmosphere, causing increasing scintillation and a corresponding degradation of the image.