We'll find out in a few weeks if we can do the same. The interesting thing without satellites is that if they shoot down everything, that means no GPS, no satellite-guided bombs, etc. I'm sure a lot of civilian operations would be affected. The military uses civilian satellites, too.
Not quite. The low earth orbit spy sats are the "low hanging fruit" that would be simple to target, and would remove our "big eyes" in space. But GPS sats are in very high orbits, I think above 10,000 miles up. There is a large "constellation" of them, and hitting a few would not take down GPS.
Most comm sats are in medium to high orbits, and are also harder to target.
THe other vulnerability of low earth orbit spy sats is that destroying them will put a cloud of debris into that altitude that might render low earth orbits unuseable for years.