The first thing I'd do is cut the bit about nothing down from nine sentences to two or three. As is, it goes past adding texture to just inspiring impatience. In fact, I'd be tempted to scrap the first four paragraphs entirely. They say that if in doubt, you should start the story as close to the start of the action as you can. Starting at the birth of the universe is as far away from this goal as it is possible to get, and should not be done unless you're sure it adds something to the story.
The second thing, while it might be atmospheric, the "do not open a room where someone committed suicide upon penalty of death" thing is the wrong sort of atmosphere,
IMO, for two reasons. On a colony ship like this you can't afford to just throw away perfectly usable volume just because some dumbass broke a window and when your problem is with suicidal people, threatening them with death is unlikely to be an effective deterrent.
Third, throwing someone out the airlock will not make them explode, not with only a single atmosphere of pressure difference. They'll suffer some observable effects of the sudden decompression, but mostly they'll just gasp and writhe until they pass out.
What might be a bigger problem is that I don't find the source of the conflict in the story so far very compelling. At the moment, the enforcer class does not seem to provide any benefit that outweighs their apparent deleterous effect on morale, which makes it difficult to take them seriously as anything but a
Diabolus ex Machina. This could work if the eighteen year old protagonist has merely misjudged the enforcer class or if he thinks the one or two jerks he's most familiar with are representative of the whole group, but not if they're legitimately dead weight that should have been spaced ages ago.
So this isn't exactly warhammer related, well i suppose i could make it so...might be interesting, perhaps i shall, some kind of fighting stuff in a 
