As far the Almaz station's solution to the recoil problem, the Russians rather ingeniously paired a set of counter-thrusters, out of the station's standard thruster nozzle assembly, to be set off - both electronically, and mechanically - by the trigger pull of the gun, so when you fired off rounds, the attitude jets would fire an appropriate amount of thrust to counter the effect. This was mentioned in the original article that I saw this thing in.
As for the DC Working Group, I'd certainly hope ASAT Warfare wouldn't be enough to make LEO so dangerous to be off limits! For one, it'd put a damper on returning to space anytime soon (2300 AD, I'm looking at you!). For two, it'd make me sad. For three, they'd have to shoot a heck of a lot of satellites to fill up that much volume! (All these are arranged in order of importance, of course
Is the DC Working Group thinking about the Soviet Fractional Bomb System, if I remember correctly, where they would "pre-position" ICBMs in orbit, then later de-orbit them as needed to strike targets as they become available? I always thought that was a particularly neat concept, really.
Also, Raellus, last time I checked, the key phrase to remember when it comes to space combat is: Eggshells With Sledgehammers. Stealth in space is a misnomer, for a lot of technical reasons involving heat, and the background heat of space. This could probably be worked around with space planes that operate super-close to Earth, I would think, but I'm not sure. If you get away from the Earth by any appreciable amount (i.e., leaving the actual atmosphere, yo), the heat requirements of your life support system alone will paint you as a super-obvious target. Unless you happen to be a robot, then you can actually chill yourself down to appreciable amounts.
God help you, however, if you ever fire your engines. :\
But yeah, I'm not sure about missiles, but in anything remotely like the near-future (i.e., the next 50 years) I could certainly see guns being a problem with space planes. Plus, depending on how high up you get, and depending on how far weaponized laser technology gets, guns might be... superfluous. Then again, that's what they said in the Jet Age, too, eh?
Time Shall Tell (TM).
Oh, and also, if anything I say turns out to be wrong and repudiated by a Reputable Source (TM), then I claim innocence and/or ignorance as my defense.