In regards to the cloaking stuff, as of current and modern technology: yeah, it's totally unfeasible to turn it into a really practical ship's cloak. Hiding the exhaust is definitely an issue, though not entirely impossible. Ion drives, though exceedingly low thrust capability, don't emit significant amounts of energy, and not enough that it would light up the IR and visible spectrum like a halogen light in a cave. Detectable if you knew when and where you were looking, but not necessarily easy. Using solid state rocket fuel or hypergolics as we do right now is impractical on a number of levels, the not even the least of which being the amount of fuel and remass that a ship would have to carry for even inter planetary travel with a contingent of people on board.
Interstellar anything is absolutely out of the question until we develop some sort of FTL drive, and if that becomes the case, then this whole cloaking point is moot. The radiation bloom from the exhaust will only travel at the speed of light as a maximum. If your ship travels superluminally, you're outrunning the light wave. It's like trying to track a supersonic jet using just the sound wave. If the jet is coming straight at you, by the time you'd have heard it, the jet would already be attacking you. In that regard, there's something of a built in cloaking effect of FTL travel, but only if we only use some sort of RADAR or LIDAR system to track inbound forces. I would venture a speculative guess that if we do figure out FTL travel, FTL communications and sensors would have to be developed concurrently - likely an outgrowth of whatever discovery would open up FTL physics.
The most widely accepted idea of FTL travel is the "moving sidewalk" theory. A person might have a top speed of 20 kph, but if they are on a moving sidewalk going an additional 10 kph, they are now travelling, from the perspective of a stationary observer, at 30 kph. While nothing in space can theoretically exceed the speed of light, there is no rule against space itself travelling FTL. In fact, it is this FTL expansion of space that is present in the inflationary theory of the current Standard Model of the universe (the Big Bang.) Essentially, if there was a way to isolate a pocket of space-time and move it, it would solve both problems. The space can go FTL, and from the perspective of the people inside the pocket of space-time, they would essentially remain stationary and avoid any unpleasant relativistic effects of speeds near that of C (time dilation, "spaghettism," ect.)
The idea of the space warfare between planets in our solar system is in essence so impractical and so costly on resources that it would be virtually impossible to conduct. While the idea of MAD seems more likely, if you're a space corporation, why on Earth, Mars, Luna, or whatever else gets colonized, would you deliberately waste resources annihilating other resources? It's a stupid enough concept here on Earth alone. We spend trillions of dollars of economic resources wiping out other trillions of dollars of resources that we're attempting to capture, just so that it doesn't end up in someone else's hands. That's here on Earth as it stands. If we're going to make it into space at all, even just to set something up on the moon, it will cost as much as the last ten wars the world has fought combined. It cost the US more than a trillion dollars to send fewer than two dozen men to the moon, and they didn't even stay for more than a week, tops. Even if we do figure out cheaper ways to get things into space, like orbital tethers, it's still such a massive undertaking that to spend the resources on interplanetary war would be so impractical and costly as to prohibit space battles. The only reason to go to war is over resources, and the gross loss would be so staggering that there could never be any net gain, ever. If the bottom line is what we're concerned about, war should already be obsolete, and going into space will certainly have to push that over the edge.
Sigh... so that's my long suit for peace on Earth. It's cheaper.
