The Alignment and the Eridani Edict
In answer to the question about whether or not the Mesan Alignment "respects" the Eridani Edict, I'll just say this. People who assume that the Alignment is in the business of casual wholesale massacre are misinterpreting a lot of what they've seen out of the Alignment. I'm not saying that the Alignment isn't perfectly prepared to wade to its boot tops through someone else's blood if that's what it takes to reach its objective, but Detweiler & Co. really aren't totally homicidal maniacs who think that going around wiping out entire planetary populations is a really fun way to spend the afternoon. More than that, from a pragmatic perspective, they recognize that it doesn't really matter what can be proved if they get into the habit of killing off planets. They have a great respect for Murphy, and they understand that "mysterious" planet-killing strikes, or planet-killing strikes which come at suspicious moments (that is, as in "Why would Manticore strike Haven at this particular moment, or vice versa, when they never did it before when things were at least equally grim?") are going to start people thinking about who might have motives to do Bad Things.
Let's consider this from the Alignment's perspective. Suppose that "someone" carries out a planet-killing attack on one or more of the Star Kingdom's home planets, or on the Haven System. The victim of said attack might assume it was the other side, although efforts to plant evidence to that effect would increase the possibility of Murphy putting in an appearance. By the same token, though, those questions about "Why now?" would probably surface. And even if the immediate assumption is that it was the work of the known enemy, eventually -- and probably within a period of a fairly short number of years -- evidence is going to emerge that it wasn't that enemy's doing. At that point, both sides (assuming there are survivors on both sides) are going to go looking for whoever it was, and when they find whoever it was, they are not going to be very happy with the responsible parties. For that matter, if it becomes evident to people who were innocent bystanders at the time of the attack that someone else carried it out, they're going to have very strong motives to figure out who it really was and why they did it.
In addition, consider this. If the Alignment uses its new, superduper, secret technology to carry out a planet-killing attack, then it had better never, ever use that same new, superduper, secret technology to do anything else. The instant it turns out that the Mesan Alignment had the capability to carry out such an attack before anyone else, suspicion is going to focus very, very tightly on the Alignment, and people are going to start looking for why it might have been convenient for the Alignment for that particular planet to end up dead. The fact that no one knows who did it right now does not begin to imply that no one will later figure out who did it.
This means that for planet-killing to work as a part of the Alignment's long-term strategy, it would have to accomplish some critical goal without starting to point fingers in the direction of a vast, secret conspiracy. And it would have to do that within an effective time frame -- that is, the desired outcome of a particular planet would have to come to fruition within a time window which would permit the Alignment to fully accomplish its long-term strategy. And that goal would have to be such that no one else would have the power/capabilities/opportunity to do to the Alignment what it had already done to someone else. Because, if the Alignment doesn't accomplish its long-term strategy before the rest of the galaxy starts figuring out who was responsible for it, then the Alignment is toast. There are very few things as likely to put together a huge alliance of otherwise potentially mutually hostile powers than the suspicion that someone is going around destroying entire planetary populations.
Moreover, there would have to be an objective which would be accomplished by killing the planet which could not be accomplished more economically -- or at least at a lower cost in total casualties (and potential reprisals) -- by some other means. Added to that, I'll simply point out that the majority of the Mesan iceberg is still below the surface as far as the books are concerned. Assuming that killing off the entire population of the planet Manticore would be part and parcel of the ultimate Mesan strategy depends on facts not yet in evidence. I'm not saying that there couldn't be circumstances under which doing exactly that wouldn't strike the Alignment as reasonable. (After all, if the Alignment should just happen to end up doing something like that, I wouldn't want any of my loyal readers pointing out "But David said they wouldn't do that!") I'm simply saying that, so far, I don't think there's been any evidence that it would strike the Mesans that way.