Usually those are referred to as Orbital Defense Platforms.
True but I doubt those actually exist in the Star Trek universe as Earth would probably have some of those instead of just those three ships things the Borg blow up without even stopping on their way to Earth.
I would imagine the Klingons would figure a way around those pretty quick.
I don't know thanks to the 24th century the Klingons don't exactly come off as tech geniuses they're more likely to just shoot at them thus likely attract the nearest Federation starship.
Seriously their idea of treating the loss of an eye is bolting an eyepatch to your head.