Why would you be so keen to make the argument that Gadaffi's victory would in fact not be a step back for the revolutionary movement in Libya? First you say that the accusation that Gadaffi is going to massacre oppositionists is dubious (it is not); then you say that the victory of the rebels would not bring more breathing space (that's something we have to admit as a possibility, but it is less likely than Gadaffi's victory closing off all hope of democratic openings). All of this cloaked in umming and ahhing - nothing is certain, it is all a gamble, we cannot know anything, you must exhaustively document the most tentative estimate of what's going on... this looks like the progress of someone slipping towards a pro-Gadaffi position as a logical consequence of knee-jerk denunciation of every thing that imperialism does.
In response to your questions:
b) it was reasonable to expect that such a thing would happen. It was only unreasonable to expect such a massacre if your starting point was that no ethnic cleansing was taking place at all. Was all the genocide in Kosovo "imperialist war propaganda"?
c and d): We do not support intervention. We warn against relying on it, we warn against trusting it, we call for vigilance against the current action evolving into a mission of conquest or subjugation. Currently, the bombing campaign is keeping the rebels from being defeated and it is aiding the rebellion. For as long as that is the primary dynamic on the ground in Libya, a movement capable of stopping the bombing should not stop it. But were this situation to change, we would call for mistrust to turn into active opposition. If we were supporting the intervention now, that would be a u-turn; support now would make it harder to galvanise opposition later. We are not supporting the intervention precisely because we recognise that at any moment mistrust will have to become active opposition. We are not taking responsibility for the later actions of the coalition, because we are making propaganda to prime the movement to oppose it later.
But that task of opposing it (rather than just warning against it) later is not helped, the anti-war case is not strengthened, if the left positions itself *now*, in the eyes of everyone who hasn't gone through a daft-left education, as bone-headed partisans of Gadaffi's right to slaughter the rebels! It is no part of principled anti-imperialism to proclaim explicitly or implicitly, that the best thing is for the Libyan conflict to take its course with the strongest coming out at the end on top of the bloody pile. Saying that now is not part of opposing imperialist adventures later.