No, there's plenty worth fighting for... and most of it is commodities carried aboard. And those vary.
Fuel is one such. ²H and ·³H, as well as ³He, have extensive promise as fusion fuels... and need cryogenic storage, which, while ³He is not uncommon, and ²H is common enough... but keeping them usefully condensed requires either cryogenics or, in the case of Hydrogen, a 4.5 to 9x mass penalty in oxidization. (The safest/easiest way to transport hydrogen, especially deuterium, is oxidized into water... because then it doesn't escape confinement by quantum tunneling.)
Food is another. For all the colonies, probably half or more are likely to be resource extraction colonies. Net exports raw materials, imports food and entertainment.Local sources (Hydroponics and domes) provide stable staples... but the harder to grow long-investment crops (especially tree-fruits) will be trade goods.
Medicines will be another. Cheaper to manufacture in bulk in scale-efficient factories... and more accurate/consistent in concentration, too. The basic staples (anti-inflammatories, analgesics, steroids, other bioregulatories) will be always be valuable. Not flashy, but always saleable. Even when stolen.
Even more important is corporate secrets... to the right buyer, retirement time!
A shipowner does everything he must to keep his ship going, because by the time they get it, it's usually become a pathological obsession. And then, there's that bit about "Space is Hell"... which they flatly deny until the day it maims or kills them.
Okay, we’re probably going to have to agree to disagree. To me that reads more about reasons for space piracy and not space combat.
I don’t think space pirates makes any sense in the setting, the economics and consequences alone would make it prohibitive in the setting. If you really want to go pirate hunting play Coriolis, the game setting was pretty much designed to support that kind of adventure. In Alien, you’re not going to duke it out with an adversary for some bananas and bandages.
Obviously in the end it’s your game. Personally I would be disappointed and think the design team clueless if they included dogfighting spaceships and space pirates in the rules. I really don’t see Alien as the setting for those kinds of adventures.
In Alien, a ship is very expensive to say the least, it’s unlikely that many are in private hands outside of the corporations. Unlike the age of sail(wind was free and wood accessible), fuel and maintenance are also expensive. You could easily spend more in fuel and repairing any damage than you would make selling any cargo won, it just doesn’t make sense on a balance sheet.
That gets us to consequences. Alien is a setting with FTL communications and powerful corporations that tolerate very little, shall we say entrepreneurial spirit. I would assume that extensive capabilities for sensor forensics exist. I can’t imagine pirates would have very long to operate before attracting attention from the authorities.
Unlike WY or the marines, pirates aren’t going to be able to re-arm expended missiles without comprehensive logistical support. Even if your ships has missiles(most probably don’t) it’s not the kind of thing you can buy without licenses and probably filing paperwork about where the missiles you already had we’re used.
Piracy in Alien takes place in boardrooms with lawyers and contracts. A commercial freighter crew is never going to repel boarders, there’s a good chance they won’t have any guns anyway. That’s part of what makes the setting so scary, it’s all mundane and workaday. You’re just hustling for a percentage until you wake up in a total nightmare.
Someone else’s cargo is only worth the effort when it’s of interest to bio-weapons division, and even then the last thing you’d want to do is start shooting.